Sunday, November 21, 2010

Balancing Chemical Equations (Introductory Stoichiometry)

A chemical equation describes what happens in a chemical reaction. The equation identifies the reactants (starting materials) and products (resulting substance), the formulas of the participants, the phases of the participants (solid, liquid, gas), and the amount of each substance. Balancing a chemical equation refers to establishing the mathematical relationship between the quantity of reactants and products. The quantities are expressed as grams or moles.

It takes practice to be able to write balanced equations. There are essentially three steps to the process:

1.Write the unbalanced equation.

•Chemical formulas of reactants are listed on the lefthand side of the equation.

•Products are listed on the righthand side of the equation.

•Reactants and products are separated by putting an arrow between them to show the direction of the reaction. Reactions at equilibrium will have arrows facing both directions.

2.Balance the equation.

•Apply the Law of Conservation of Mass to get the same number of atoms of every element on each side of the equation. Tip: Start by balancing an element that appears in only one reactant and product.

•Once one element is balanced, proceed to balance another, and another, until all elements are balanced.

•Balance chemical formulas by placing coefficients in front of them. Do not add subscripts, because this will change the formulas.

3.Indicate the states of matter of the reactants and products.

•Use (g) for gaseous substances.

•Use (s) for solids.

•Use (l) for liquids.

•Use (aq) for species in solution in water.

•Write the state of matter immediately following the formula of the substance it describes.

Worked Example Problem

Tin oxide is heated with hydrogen gas to form tin metal and water vapor. Write the balanced equation that describes this reaction.

1.Write the unbalanced equation.

SnO2 + H2 → Sn + H2O

Magic Rocks in Space

Have you ever wondered how a chemical crystal garden, like Magic Rocks, would grow in space? These photos show the difference between a silicate chemical garden grown on the International Space Station and one grown in full gravity on Earth.

Mercury Beating Heart

The Mercury Beating Heart is a popular chemistry demonstration/experiment in which a blob of mercury is made to pulsate, resembling a beating heart. The mercury beating heart requires only a few materials and is easy to set up, though it's a little tricky to get going.

Mercury Beating Heart Materials

•drop of mercury

•dilute sulfuric acid (battery acid strength works)

•potassium permanganate or potassium dichromate solution or crystals

•iron wire or nail

•watch glass or petri dish

Perform the Mercury Beating Heart Demonstration

1.Place a drop of mercury into a dish.

2.Cover the mercury with sulfuric acid.

3.Add a small amount of potassium permanganate or potassium dichromate.

4.Slowly move the iron wire or nail so that the tip is near the mercury, but not quite touching it. The distance depends on the ratio of the concentration of the acid and oxidizer, so you'll need to play with this to find the sweet spot.

5.Once you have the distance right, the mercury will contract into a rounded ball and then spread out to touch the iron and contract again. The 'beating heart' will beat for about 20 seconds.

Learn how the Mercury Beating Heart works..

Wednesday, September 22, 2010

On This Day in Science History - September 22 - Isotopes

September 22nd marks the passing of Frederick Soddy. Soddy was an English chemist who investigated the assortment of newly discovered elements that were decayed from radium, thorium and uranium. At this time, many of these elements had names like mesothorium, Radium A, B, C, D, E, F and Uranium X, each with a different half-life. Chemists were trying to separate elements like radiothorium from thorium but could not accomplish the task. Soddy theorized they were all the same elements and could not be separated chemically. They had slightly different atomic masses, but were the same elements. He gave the name 'isotope' to the atoms in this elemental mixture. He cited radium D and thorium C were actually two different isotopes of lead and acted the same as lead chemically.

He couldn't explain his theory with the current science. When the neutron was discovered by James Chadwick, Soddy's isotope theories suddenly made more sense. He also described the mechanics of radioactive decay. Alpha decay was the emission of a helium nucleus, 2 protons and 2 neutrons that lowered the atomic number by 2 and the mass by 4. Beta decay involved the emission of a beta particle (electron) that raised the atomic number by 1.
Soddy was awarded the 1921 Nobel Prize in Chemistry for this work and his theory. Find out what else occurred on this day in science history.

Can You Balance an Egg on the Equinox?

The autumnal equinox is Wednesday, September 22nd, 2010. This is the first day of fall in the northern hemisphere, or the first day of spring in the southern hemisphere. Are you familiar with the urban legend that it's easier to balance an egg on end on the equinox than on other days of the year? Test it and see! The autumnal equinox one of the two times during the year when the sun crosses the celestial equator and the spin axis of the Earth points 90 degrees away from the sun. Why should this affect your ability to balance an egg on end? The premise is that aligning the gravitational pull of the Sun with that from the center of the Earth should somehow make it easier to balance any object.

Test the Egg-Balancing Hypothesis Yourself

Take a carton of eggs and try balancing the eggs on end today. Can you stand any of them up (without resorting to tricks like putting salt under the eggs)? Can you stand eggs on their small ends as well as their large ends? Keep track of your results and repeat the process on the equinox. Do you note any differences? An easier hypothesis to test is: Eggs can only be balanced on-end on the equinox. If you can balance an egg today, you've disproven the hypothesis. It's that easy!

One thing I find neat about egg-balancing is that a balanced egg will hold its position until a vibration knocks it down. How long can you keep an egg standing?

Gemstone Color Chemistry

Gemstones are minerals that are considered pretty enough to use for jewelry and decorations. In many cases, the pure form of the mineral is clear (e.g., quartz), while impurities produce lovely colors, like the yellow and purple of the ametrine pictured here. In the case of ametrine, the quartz is discolored by iron. Are you interested in learning which transition metals are responsible for the color of your favorite gemstone?

Detergent and Bath Salts May Form Deadly Hydrogen Sulfide Gas

Mixing household chemicals, particularly cleaners, can produce toxic or even deadly fumes. You may be aware you should never mix bleach and ammonia or bleach and vinegar, yet might not realize trying to boost the cleaning power of detergent or toilet bowl cleaner is similarly dangerous. Sulfide salts or solutions react with acids to form hydrogen sulfide gas (H2S, shown). This is the chemical responsible for the rotten-egg smell, but exposure to hydrogen sulfide eventually deadens the sense of smell and can kill you. The gas is heavier than air, so it can settle toward the ground or find its way down stairs. If you smell the rotten egg odor when chemicals are mixed, it's a good idea to call 911 rather than just air out the room and return later because the gas could pose a threat to your family, pets and neighbors.

Mixing toilet bowl cleaner and bath salts or detergent and bath salts has been used as a suicide method in Japan and the UK. Readers should be aware this is a particularly selfish way to poison one's self, since the gas has the potential to harm rescue workers and innocent bystanders.

Tuesday, September 21, 2010

Nine new anthrax infections in Bangladesh

The number of anthrax infections continues to rise in Bangladesh, with nine new cases reported by officials with the Institute of Epidemiology, Disease Control and Research.

The latest cases, in the Pabna and Meherpur districts, bring the total number of anthrax infections since August 18 to 517 cases. No news of fresh infection of animals has been reported, however, an official with the livestock department told the nine new cases, seven were found in Gangni and one in Mujibnagar upazila in Meherpur and one in Shathia upazila in Pabna. The districts where the cases of infected people were found are Narayanganj, Pabna, Sirajganj, Meherpur, Kushtia, Tangail, Manikganj, Shatkhira, Lalmonirhat and Rajshahi.

Institute of Epidemiology, Disease Control and Research director Mahmudur Rahman told that vaccination of livestock is the main way to control anthrax.Bidhan Chandra Das, the assistant director of health and administration at the Department of Livestock, agreed, saying that his office was busy vaccinating animals in both the affected areas and in surrounding areas.“We are also distributing leaflets to make the people aware about anthrax,” Das told

The anthrax outbreak began on August 18 when villagers in the Sirajganj district in central Bangladesh became infected, reports. The cause was traced to anthrax-infected cows that were sold for meat to nearby villagers. All of the reported infections so far have been cutaneous and no deaths have been reported.
Anthrax is a potentially deadly, highly contagious disease. Cutaneous forms of anthrax are the most treatable, causing death in 20 percent of those infected. Inhalation anthrax, generally the result of a deliberate attempt to release anthrax spores, is far more deadly, causing death in 80 percent of those infected.

Anthrax infects 586 in Bangladesh

The total number of confirmed human anthrax infections in Bangladesh has reached 586 with three new cases detected in the last 48 hours.

The Institute of Epidemiology, Disease Control and Research, under the Ministry of Health and Family Welfare, told that one of the new caseswas detected by government health officers in Chuadanga. The remaining two cases were found at Bheramara upazila of Kushtia and Gangni upazila of Meherpur.
Cases of anthrax infection have been found in 12 districts since the disease first broke out in Sirajganj, IEDCR officials told

On This Day in Science History - September 21 - Bubble Chambers

September 21st is Donald Glaser's birthday. Glaser is an American physicist and neurobiologist who was awarded the 1960 Nobel Prize in Physics for the invention of the bubble chamber.

The bubble chamber is a detection device for particle physics that works on the same basic principle as the cloud chamber. A vessel is filled with a transparent liquid (usually liquid hydrogen) heated to just below its boiling point and aligned with a magnetic field. When the scientist is ready to take a reading, a piston is used to expand the chamber. This causes the liquid to become superheated. Any charged particles passing through the vessel will ionize the liquid and cause bubbles to appear along the particle's path. The bubble density and path shape can give information on the type, charge and lifetime of the particles.

Bubble chambers have been replaced by newer methods of detection in modern particle research laboratories, but they still have a place in demonstrations and education. The photographs taken of bubble trails bring the invisible world of particle physics to a light a student can see, measure and understand. Find out what else occurred on this day in science history.

Bangladesh says anthrax spreading in the country

DHAKA, Bangladesh – Bangladesh's government says anthrax has spread in the country, with some 585 people contracting the disease since late August.

The government's Institute of Epidemiology, Disease Control and Research released the figures Monday, reporting cases of anthrax in 12 of the country's 64 districts. So far, none of the victims have died and none are seriously ill.

While anthrax is not new to Bangladesh, there's no record of it spreading so widely.

The institute said that initially, 38 villagers were sickened by the bacterial disease in northern Sirajganj district after infected cows were slaughtered.

Humans typically get anthrax from touching infected animals or animal products. Human infections are potentially fatal.

Inkless Metal Pen Writes "Forever"

Back when I took nuclear physics, we had access to lead bricks used for shielding. We used the bricks for other than their intended purpose, such as building blocks, paper weights, and writing utensils. Lead makes a pretty respectable pencil, providing you don't mind the toxicity of the... well, lead. If you liked the look of lead with the inconvenience of the brick, Geekosystem reports on the release of an inkless pen that works on the same principle. The pen uses a metal alloy tip, which writes by leaving metal on the writing surface. The pen works upside-down and underwater and leaves an indelible mark. The pen (really more like a pencil) does contain lead and other metals kids shouldn't be eating, so it is recommended for adult use only. If you're interested, you can get your very own inkless metal pen from Vat19.

Difference Between Celsius and Centigrade

Depending on how old you are, you might read 38°C as 38 degrees Celsius or 38 degrees centigrade. Why are there two names for °C and what's the difference? Here's the answer:

Celsius and centrigrade are two names for essentially the same temperature scale (with slight differences). The centrigrade scale is divided into degrees based on dividing the temperature between which water freezes and boils into 100 equal gradients or degrees. The word centigrade comes from "centi-" for 100 and "grade" for gradients. The centigrade scale was introduced in 1744 and remained the primary scale of temperature until 1948. In 1948 the CGPM (Conference General des Poids et Measures) decided to standardize several units of measurement, including the temperature scale. Since the centigrade was in use in France and Spain as a unit of angular momentum and could refer to any scale divided into 100 parts, a new name was chosen for the temperature scale: Celsius.

The Celsius scale remains a centigrade scale in which there are 100 degrees from the freezing point (0°C) and boiling point (100°C) of water, though the size of the degree has been more precisely defined. A degree Celsius (or a Kelvin) is what you get when divide the thermodynamic range between absolute zero and the triple point of a specific type of water into 273.16 equal parts. There is a 0.01°C difference between the triple point of water and the freezing point of water at standard pressure.

How Fluoride Works

Fluoride is the fluorine ion added to toothpastes and dental rinses to help protect your teeth from cavities. While increasing the concentration of systemic fluoride (e.g., through fluoridating drinking water) has not been proven to reduce the incidence of tooth decay, direct contact between fluoride and teeth strengthens and helps remineralize damaged enamel. Here's how it works:

•The calcium and phosphate compound which makes up tooth enamel is a modified form of hydroxyapatite, which is susceptible to attack by acids. Bacteria that thrive on the sugars found in the mouth multiply on dental surfaces and produce acids.

•Mechanical brushing of teeth dislodges these bacteria and rinses them away, but doesn't do anything to address the ongoing damage to enamel from acid exposure. Fortunately saliva neutralizes these acids and teeth use compounds found in saliva to remineralize the enamel. So, as long as the rate of demineralization and the rate of remineralization remain in balance, teeth remain strong and healthy.

•When more minerals are lost from teeth than are replaced, dental caries or cavities form. Fluoride helps by interacting with hydroxyapatite to form a stronger compound that is less-susceptible to acid attack. Also, fluoride remineralizes damaged enamel (though it can't fix a cavity once one has formed). There is some evidence fluoride may inhibit the growth of bacteria on teeth or limit their capacity for producing acid.

•Even though you spit out toothpaste and probably rinse your mouth, enough fluoride remains on your teeth and in your saliva to confer protection for a while after brushing your teeth or using a fluoridated rinse.

Friday, July 2, 2010

Messi in harness as Argentina promise fireworks

Pretoria, July 2 ( - Argentina were boosted on Friday when Lionel Messi trained normally ahead of the World Cup quarter-final against Germany while coach Diego Maradona pledged his men would stay true to their attacking style.
"It would be a sin to change now. I am not going to play 4-4-2," Maradona vowed ahead of Saturday's showdown at Cape Town.Messi, who reportedly had a cold which curtailed his training session on Thursday, has recovered and should be fit to start."The best news of the day at the University of Pretoria was the return to training of Lionel Messi - the fright has passed ... tomorrow he will be in the starting line-up against Germany in Cape Town," Clarin daily newspaper reported.

Maradona bestrides Argentina v Germany rivalry

   Cape Town, July 2 ( - Diego Maradona and Joachim Loew were at opposite ends of the soccer spectrum when Argentina and Germany contested the 1986 and 1990 World Cup finals but the matches made a deep and lasting impression on both men. Those two games are the most important in what has developed into one of the game's great rivalries and the latest instalment and 19th in all takes place Saturday when they meet in Cape Town battling for a place in the World Cup last four. Current Argentina coach Maradona was at his peak in 1986, as he captained his country to their second World Cup, scoring five goals on a run culminating in a thrilling 3-2 final victory over the then-West Germany. Some of the game's most iconic images were carved in the Mexico sunshine -- Maradona poised, ball at feet, about to take on a line of six Belgian defenders, Maradona punching the ball past Peter Shilton for his infamous "hand of God goal" and Maradona, slaloming through the English defence to score one of the all-time great World Cup goals to settle the quarter-final. In 1990, Argentina kicked and fought their way to the final but by the time they faced the Germans again they were hampered by suspensions to key players and Germany ground out a revenge 1-0 win via a late Andreas Brehme penalty with a near burnt-out Maradona's team having two men sent off.

For current Germany manager Loew, struggling to make an impact as a player in the 80s and embarking on his coaching career by the 1990 tournament, Maradona was everything.

Brazilians fall to Oranje ambush

  Port Elizabeth, July 2 ( - Brazil's dreams of a sixth World Cup title were shattered as the Netherlands came from behind to claim a famous 2-1 win in an enthralling quarter-final here on Friday. An own goal by Felipe Melo - who was to be sent off later - and a Wesley Sneijder header enabled the Dutch to overturn Robinho's early opener for Brazil and completely turn around a match that, at half-time, the five-time world champions appeared destined to win comfortably. The defeat means Brazil's campaign has ended at the quarter-final stage for the second successive World Cup while the Netherlands can look forward to a semi-final against Ghana or Uruguay having avenged their 1994 and 1998 last-eight defeats by the Brazilians.The Dutch cause had not been helped by losing centre-back Joris Mathijsen to a knee injury minutes before kick-off. The consequent disruption to their defence was quickly apparent, and Robinho had already had one effort chalked off because of a debatable offside call against Dani Alves by the time he gave the Selecao a tenth-minute lead. Melo delivered a ball from deep inside his own half through the heart of the Dutch defence, Robinho's run went untracked by John Heitinga and the forward was able to place his shot beyond the left glove of Maarten Stekelenburg. Juan might have made it two midway through the half. The Roma star got across his marker to meet an Alves cross at the near post but his shot was lifted high over the bar.

Heitinga, who had already been booked for an off-the-ball trip on Luis Fabiano, was fortunate not to be sent off for a foul on Kaka as the Brazilians started to dominate. A Robinho dribble, a Fabiano flick and suddenly Kaka was curling a shot towards the top corner, forcing Stekelenburg into an acrobatic save. Sneijder's comfortably-saved free-kick was the only Dutch strike on goal before the break and he and his team-mates had reason tbegrateful to Stekelenburg once more seconds before the interval, when his fingertips diverted Maicon's drive into the side netting.

There seemed no way back for the Dutch at that stage. Yet within eight minutes of the restart they were level, thanks in no small part to a free-kick won by Arjen Robben's dive close to the right touchline. The set-piece was taken short, enabling Sneijder to work the ball into space and deliver a left-footed inswinger into a congested goalmouth. Cesar came off his line to try and punch the ball clear but collided with Melo and the ball skimmed off the midfielder's head and into the net. Kaka had a chance to re-establish his side's advantage when Mathijsen's replacement, Andre Ooijer, sliced a clearance to him on the edge of the area. But the playmaker's shot was placed narrowly wide and, three minutes later, Dirk Kuyt flicked on Robben's corner and Sneijder found space in the six-yard box to head the Dutch into the lead. An afternoon that had started so positively for Brazil began to take on a nightmarish tinge when Melo was shown a straight red card for a stamp on Robben with 18 minutes left. Cesar pulled off a fine stop to prevent Sneijder from claiming his second and only a last-ditch tackle ended Kuyt's surge through the Brazilian defence as the Dutch soaked up the late pressure and made their numerical advantage count on the counter attack.

BNP to support, not join Jamaat agitation

Dhaka, July2 ( BNP will not be participating in the programmes declared by its key opposition ally Jamaat-e-Islami but fully support those to force the release of their top leaders including chief Matiur Rahman Nizami.

Secretary general Khandaker Delwar Hossain revealed his party's stance at a press briefing after a meeting on Friday morning between the party's policymakers and leaders of associate organisations.
He said, "We've condemned the arrest of the Jamaat leaders. However, the party's agenda are their own and they will carry it out alone. However, they have BNP's full support." Delwar said the Jamaat leaders were being persecuted for supporting the agitation against the government. The government brought false charges after arresting Jamaat chief Matiur Rahman Nizami, secretary general Ali Ahsan Mohammad Mojaheed and central executive committee member Delwar Hossain Sayedee, he alleged.
He pointed out that the leaders have been arrested in one case, and remanded for others cases and termed the strategy of the government 'undemocratic' and 'illegal'. Jamaat has carried out countrywide agitation and protest programmes on June 30 and July 1 demanding release of their leaders. The fundamentalist party held special prayers at mosques throughout the country for their release. The Jamaat trio were remanded in police custody for 16 days in five cases on Wednesday.

Ghana pay for penalty misses

Johannesburg, July 2 ( - Uruguay claimed their first World Cup semi-final appearance in 40 years after a pulsating 4-2 penalty shootout win over heartbroken Ghana at Soccer City on Friday.

Uruguay goalkeeper Fernando Muslera saved skipper John Mensah and Dominic Adiyah's attempts after the quarter-final had been locked at 1-1 after extra time.

Two-time World Cup winners Uruguay will now play the Netherlands in the semi-finals in Cape Town on Tuesday.

Ghana could have won the match in the last minute of extra-time but leading scorer Asamoah Gyan sent a penalty crashing off the crossbar after Luis Suarez had been sent off for deliberate handball on the goal-line. Ghana were bidding to become the first African team to win through to the semi-finals of the World Cup after Cameroon (1990) and Senegal (2002) had fallen in the last eight.
The Ghanaians scored first through Sulley Muntari two minutes into first-half stoppage time before Diego Forlan equalised with a brilliant free kick in the 55th minute.

In a pulsating quarter-final before 84,017 fans, Ghana led after Inter Milan midfielder Muntari let fly with a 30-yard effort which swerved and beat the diving Muslera into the bottom-left corner.

Muntari was having his first start of the tournament after coming in for the suspended Andre Ayew after being close to being sent home. Muntari, who has a history of clashes with the management of his national side, had a dressing-room bust-up with Ghana's Serbian coach Milovan Rajevac earlier in the tournament. Man-of-the-match Forlan equalised with a spectacular direct free kick 10 minutes after the resumption. The influential Atletico Madrid star sent his free kick over the three-man defensive wall and beyond Richard Kingson's reach into the top of the net after Ghana had threatened to take the game away from the Uruguayans. Both teams went at each other in pulsating end-to-end action with fierce tackles and plenty of goalmouth action before the quarter-final went into extra time.Uruguay, who last reached the semi-finals in 1970, will be without defender Jorge Fucile for the game after his second yellow card with Suarez also sitting out the game.Just before half-time Uruguay also lost their skipper and key defender Diego Lugano with an injured right knee and he was replaced by Andres Scotti.

This Day in Science History - July 2 - Hans Bethe

July 2nd is the birthday of Hans Bethe. Hans Bethe was a German-American physicist who was awarded the 1967 Nobel Prize in Physics for describing how stars create their energy. He was in a good place to work out ideas in atomic and nuclear physics when he worked in the theoretical division of the Manhattan Project to build America's atomic bomb. He was part of the team that calculated the critical mass necessary for a chain reaction and later worked on the implosion method to start that chain reaction.

After the war, President Truman announced the hydrogen bomb project and Bethe joined the project but hoped it would prove an impossible task. His personal feelings against atomic and thermonuclear weapons showed when he joined Einstein's Emergency Committee of Atomic Scientists against nuclear testing and the arms race. He also played a role in the eventual ban on atmospheric testing and the SALT I Anti-Ballistic Missile Treaty.

Find out what else occurred on this day in science history.

Colored Smoke Recipes

I get a lot of questions about whether the recipes that you can find online for making colored smoke bombs are valid. Yes, they are, but... you have to keep in mind the colored "smoke" is not made by burning the dyes to change the color of normal (gray or white) smoke. You can make black smoke by releasing a lot of soot into the air, or yellow smoke by releasing elemental sulfur, but most colored smoke is produced by vaporizing organic dyes. You can't use just any dye. For example, most clothing dyes will not work. Pigments from ink pens or food coloring will not work. While the proper composition will make colored smoke even if you ignite a pile of it in the open, the "trick" to getting clouds of colored smoke is to heat the dye and force it through a small hole. So... if you want to make colored smoke, use one of the mixtures intended to produced colored smoke, don't substitute chemicals, and encase the mixture in a ball or smoke cylinder. Insert your fuse, seal the container with a bead of glue, light the smoke bomb and enjoy! Try it...

Nuclear Fission Versus Nuclear Fusion

Nuclear fission and nuclear fusion both involve radioactivity, both yield enormous amounts of energy, and both are used in nuclear weapons. So, how can you tell them apart?

Fission reactions involve breaking large atomic nuclei into smaller pieces. For example, uranium can be fissioned into strontium and krypton.

Fusion reactions involve fusing or joining atomic nuclei together. The products of fusion will contain more protons or neutrons than the reactants. For example, helium (atomic number of 2) is produced in the sun from hydrogen (atomic number of 1) through nuclear fusion.

SEX Molecule

I've had the chemical structure for Sodium Ethyl Xanthate up for quite a while, which bears the acronym "SEX", but there is another molecule that is more deserving of the name:
This molecule does not exist in nature, but the structure is amusing. The systematic name for SEX is [3-[2-[3-[7-[2-[[3-[[4-benzyl-3-hydroxy-2-[3-hydroxy-4-(3-hydroxy ​propyl)phenyl]phenyl]-hydroxy-methyl]-4-[2-[3-(2-hydroxyethyl)phenyl]propyl]cyclohexyl]methyl]phenoxy]-2-[4-[3-[(4-ethyl-2,3-dihydroxy-phenyl)methyl]phenyl]-3-[2-[2-[2-hydroxy-3-[3-[2-[3-(2-tetra​ hydropyran-2-ylethyl)phenyl]ethyl]phenyl]cyclohexyl]ethyl]phenyl]​ butyl]-9,10-dihydroanthracen-1-yl]-1,2-dihydroxy-propyl]-5-(2-hydroxyethyl)-4-methyl-phenyl]phenyl]-[2,6-dihydroxy-3-(2-hydroxyethyl)phenyl]methanone

Saturday, May 29, 2010

This Day in Science History - May 29 - Peter Higgs

May 29th is Peter Higgs birthday. Higgs is a British physicist who proposed a particle that was responsible for the origin of mass called the Higgs boson. This particle is a centerpiece of the modern Standard Model of elementary particles, but has yet to be detected. The Large Hadron Collider (LHC) at CERN may produce the energy levels necessary for its creation and prove or disprove the current Standard Model.

Happy Birthday Dr. Higgs! Find out what else occurred on this day in science history.

Serious Side Effects from Recalled Tylenol Products

You may remember back when the Tylenol recall was first getting underway, McNeil/Johnson & Johnson assured consumers the tribromoanisole contamination merely produced a musty odor and some nausea. They were understating the side effects of the contamination, as many of you know from firsthand experience, plus there were other quality concerns besides that single contaminant. Now the FDA is looking into 775 serious side effects, including 7 deaths since May 1, reported from exposure to the contaminated drugs. McNeil maintains that its latest recall of children's drugs was precautionary and not "undertaken on the basis of adverse medical events". The House Committee on Oversight and Government Reform is undertaking hearings to examine the recall. In the meantime, how many of you continue to use Tylenol, Motrin, Benadryl, or any of the other drugs produced by McNeil/Johnson & Johnson? If you haven't checked to see whether the product you are using has been recalled, here's the list from McNeil's website.

Carbonated Ice Cream Recipe

Have you tried fizzy ice cream? It has the flavor and bubbles of an ice cream float without the soda. It's an extremely easy recipe to try. It doesn't even require a freezer; you just need dry ice. I've had a recipe for vanilla dry ice ice cream up for a while, but here's a chocolate recipe, along with a few tips and tricks I learned making the ice cream:

Carbonated Ice Cream Ingredients

2 cups heavy cream

2 cups half and half

1 cup chocolate syrup

1/2 cup sugar

1 teaspoon vanilla

1/8 teaspoon salt

dry ice

Make Dry Ice Ice Cream

You'll get a better texture for your ice cream if you crush your dry ice. The easiest way to do this is to put the dry ice into a paper bag and smash it with a mallet or walk on the bag. The ice crushes easily so you don't have to get medieval on it.

In a very large bowl, mix all of the ingredients except for the dry ice.

Stir in the dry ice a little at a time. "A little at a time" is the key point here, because if you add a lot of dry ice at once you'll get mountains of bubbles that will overflow your bowl. The bubbling will continue as long as any dry ice remains.

solid ice cream. The ice cream will be very cold, so be careful when eating it.

You can store uneaten ice cream in the freezer.

The dry ice sublimates to form carbon dioxide gas. The carbon dioxide is perfectly safe... you drink it in soda all the time. The only risks from the recipe are weight gain (not exactly a low-cal, low-fat recipe) and frostbite (use gloves if you plan to handle the dry ice and don't eat dry ice chunks). If you have leftover dry ice, there are many other projects you can try.

Barbeque Carcinogens

One of the best parts of summer, in my opinion, is barbeque. See that marshmallow? It's perfect. Brown all the way around, gooey all the way to the center. You know it will melt in your mouth. I didn't take the photo. That's because my marshmallows inevitably burst into flame and end as cinders with cold, white centers. I imagine either type of toasted marshmallow contributes to your cancer risk. So does anything charred, like seared steak or hamburgers from the grill or even burnt toast

The carcinogen (cancer-causing agent) is mainly benzo[a]pyrene (structure is shown), though other polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs) are present and can cause cancer, too. PAHs are in smoke from incomplete combustion, so if you can taste smoke on your food, expect it contains those chemicals. Most of the PAHs are associated with smoke or char, so you can scrape them off of your food and reduce your risk from them (though that kind of defeats the point of a toasted marshmallow). HCAs, on the other hand, are produced by a chemical reaction between meat and high or prolonged heat. You'll find these chemicals in fried meat as well as barbeque. You can't cut or scrape away this class of carcinogens, but you can limit the amount that is produced by cooking your meat just until it's done, not blackening it into oblivion

Wordless Wednesday - Can You Guess What This Is?

Can you guess what this is? I'll give you a hint: The photo was taken at Brookhaven National Lab and it involves gold ions. The image was produced by the Solenoidal Tracker (STAR) Time Projection Chamber, a large, 3-D digital camera at Brookhaven's Relativistic Heavy Ion Collider (RHIC).

Brookhaven National Lab

Make a Sparkler

Fireworks are a bit like food. They are made according to recipes. Sometimes spectacular results can be achieved from a simple recipe, using only a few basic ingredients. Just like sometimes you want to pop a frozen dinner in the microwave (or buy fireworks from a store), sometimes you want to make dinner (or make your own pyrotechnics). If you're feeling creative, try making your own sparkler. Who knows, you may discover a hidden passion for pyrotechnics

Sparklers are a handheld 'fireworks' that don't explode (pyrotechnic devices). They are easy to make, plus you can use your knowledge of chemistry to make colored fire.

Difficulty: Average

Time Required: minutes to make, several hours drying time

Here's How:

Mix the dry ingredients with enough dextrin solution to make a moist slurry. Include the strontium nitrate if you want a red sparkler or the barium nitrate if you want a green sparkler.

Dip the wires or sticks in the sparkler mixture. Be sure to leave enough uncoated space at one end to safely grasp the finished sparkler.

Allow the mixture to dry completely before igniting the sparkler.

Store sparklers away from heat or flame, and protected from high humidity.


Source is L.P. Edel, "Mengen en Roeren", 2nd edition (1936), p.22, as cited from Wouter's Practical Pyrotechnics

Parts are by weight.

Be certain the sparkler is 'out' and cooled before discarding it. This is easily accomplished by dipping the stick in a bucket of water.

Firework use is restricted or prohibited in some areas. Please check your local laws before burning sparklers, whether you purchase them or make them yourself.

Saturday, April 17, 2010

This Day in Science History - April 17 - Giovanni Riccioli

The Moon has its own unique geography. We have names for the smooth dark areas like Mare Serenitatis and Mare Tranquillitatus, otherwise known as the Sea of Serenity and Sea of Tranquility. The craters have names like Tycho, Copernicus and Archimedes.

One man is largely responsible for these names, Giovanni Riccioli celebrates his birthday today. Riccioli was one of the most prominent astronomers of his time and created a detailed atlas of the Moon. His names for the Maria and craters have lasted to current times.

Do Goldfish Turn White in the Dark?

My kids were making dinner the other night and asked me about a fun fact they read on the side of a box of fish filets. The 'fact' said goldfish kept in the dark will turn white. Both the chemistry and biology of fish color are pretty complex. Fish color can change in response to their environment (including lighting), heredity, diet, age, and other factors. The color changes range from temporary to permanent. The fun fact was an oversimplification. Your goldfish would become pale from lack of light, but unless you either starve it or feed it foods lacking pigments, it won't turn white.

Learn more about goldfish colors...

Why Students Fail Chemistry

The semester is nearing its end at many schools. Are you concerned you may not pass your chemistry class? It's not too late to learn the concepts or to make a change in your study habits. Knowing reasons why students fail may help you avoid making the same mistakes.

Top Ways to Fail a Chemistry Class
Avoid these mistakes to help ensure success in your chemistry class.

1. Don't Show Up

Possibly one of the easiest ways to ensure failure is to not attend class. It's possible to teach yourself chemistry without ever setting foot in a classroom, but learning a subject isn't the same as passing a class. If you don't put in the time, you probably won't know what is expected of you for exams. You won't know what problem sets are due. You can't do labs if you aren't there. Even if there isn't an attendance policy, it helps to put in face-time.

Do Debbie Meyer and Evert Fresh Green Bags Work?

Debbie Meyer Green Bags and Evert-Fresh Green Bags are a storage product advertised as capable of keeping produce fresh for up to 30 days. They are plastic bags that contain zeolite that absorbs ethylene gas. Plants use ethylene as a hormone. One of its actions is to ripen fruit, so if you can reduce the concentration of ethylene around an apple, for example, it shouldn't get over-ripe and mushy as quickly.

Do Green Bags work? Well... they probably do lower the levels of ethylene inside the plastic bag, so if you are comparing how long fruits and vegetables stay fresh in Green Bags as compared with other plastic bags, you might see an improvement. Or you might not, since ripening is not necessarily why produce spoils. Strawberries and raspberries, for example, usually mold long before the fruit itself goes bad. Most produce really shouldn't be stored in plastic bags, so if you really want to extend its shelf life, leave the produce in the open (tomatoes and bananas) or use paper bags or loosely-wrapped damp paper towels. Some people have reported good results with Green Bags for certain types of produce, such as apples and peppers. I am unaware of anyone who has gotten the bags to preserve produce for the full 30 days.

Would I buy them? No, because my kids eat everything I bring into the house within three days. If I didn't have kids and if the bags were effective, then I would consider the expense. Generally speaking, however, the shelf life of most produce is reduced by storing it in plastic, zeolite or no zeolite, because the humidity inside the bag is so high. You can help your produce last by keeping it cool and by allowing air circulation, which naturally reduces ethylene and other plant hormone levels in the air.

Have you tried Green Bags? Feel free to post a comment to share your experiences with other readers.

Wednesday, April 7, 2010

This Day in Science History - April 7 - World Health Day

April 7th is World Health Day. World Health Day is sponsored by the World Health Organization to promote awareness of a specific theme of concern for WHO. The 2010 theme is '1000 Cities, 1000 Lives'. They are collecting 1000 stories of people contributing to health awareness and profiling 1000 cities around the world that promote health or cleanup campaigns.

Find out what else occurred on this day in science history.

1823 - Jacques-Alexandre-César Charles died.

Charles was a French physicist and inventor who described the relationship between the volume and absolute temperatures of ideal gases known as Charles's Law. He also built the first hydrogen filled balloon and the first manned hydrogen filled balloon.

1817 - Francesco Selmi was born.

Selmi was an Italian chemist who was a pioneer in colloid chemistry. He also coined the term 'ptomaine poisonoing' while studying putrification and poisons.

Scientists Discover a New Element - First Atoms of Element 117 Produced

When you go looking for new elements, you already know how many protons they are going to have. It's a matter of finding the new element, making it, or detecting decay products that could only have come from the new element. This is a tricky process because the higher atomic weight elements are difficult to produce and very, very short-lived. It's rare for new elements to be discovered, so I'm excited that a team of Russian and American scientists report that they have created 6 atoms of element 117. Atoms of the new element were produced by firing atoms of calcium (atomic number 20) at a berkelium target (atomic number 97) to produce atoms with 117 protons.

At this time, no 'real' name for element 117 has been proposed, so you can call it element 117 or by its placeholder name, ununseptium (which means 117). Names are proposed for elements only after their existence has been confirmed by a second source. The New York Times has more details about the discovery or you can read the report of the element's production in Physical Review Letters.

Tuesday, April 6, 2010

Who Invented the Periodic Table?

Question: Who Invented the Periodic Table?

Do you know who described the first periodic table of the elements that ordered the elements by increasing atomic weight and according to trends in their properties? I'll give you a hint. It was not Dmitri Mendeleev. The actual inventor of the periodic table is someone rarely mentioned in chemistry history books.

Answer: If you answered "Dmitri Mendeleev" then you might be incorrect. Dmitri Mendeleev presented his periodic table of the elements based on increasing atomic weight on March 6, 1869, in a presentation to the Russian Chemical Society. While Mendeleev's table was the first to gain some acceptance in the scientific community, it was not the first table of its kind.

John Newlands had published his Law of Octaves in 1865. The Law of Octaves had two elements in one box and did not allow space for undiscovered elements, so it was criticized and did not gain recognition.

What Is Distillation?

Question: What Is Distillation?

Answer: Distillation is a widely used method for separating mixtures based on differences in the conditions required to change the phase of components of the mixture. To separate a mixture of liquids, the liquid can be heated to force components, which have different boiling points, into the gas phase. The gas is then condensed back into liquid form and collected. Repeating the process on the collected liquid to improve the purity of the product is called double distillation. Although the term is most commonly applied to liquids, the reverse process can be used to separate gases by liquefying components using changes in temperature and/or pressure.

Distillation is used for many commercial processes, such as production of gasoline, distilled water, xylene, alcohol, paraffin, kerosene, and many other liquids. Types of distillation include simple distillation (described here), fractional distillation (different volatile 'fractions' are collected as they are produced), and destructive distillation (usually, a material is heated so that it decomposes into compounds for collection).

Who Was the First Chemist?

Question: Who Was the First Chemist?

Chemistry has been around for a very long time! Do you know the name of the first chemist in recorded history? Would it surprise you that the first chemist was a woman?

Answer: The first known chemist was a woman. A Mesopotamian cuneiform tablet from the second millenium B.C. describes Tapputi, a perfumer and palace overseer who distilled the essences of flowers and other aromatic materials, filtered them, added water and returned them to the still several times until she got just what she wanted. This is also the first known reference to the process of distillation and the first recorded still.

How to Get Mosquitoes to Bite Your Friends

... not that actually want mosquitoes to bite your friends, but I think you will agree you don't want to be bitten. Here's a list of things that attract mosquitoes. If you want to avoid an encounter with the vampiric swarm you can avoid doing any of these things yourself or you can encourage those around you to do them. Whatever works.

Wear Dark Clothing

Many mosquitoes use vision to locate hosts from a distance. Dark clothes and foliage are initial attractants.


You give off more carbon dioxide when you are hot or have been exercising. A burning candle or other fire is another source of carbon dioxide.

Eat Bananas and French Fries

You release more lactic acid when you have been exercising or after eating certain foods (e.g., salty foods, high-potassium foods).

Wear Perfume or Cologne

In addition to perfumes, hair products, and scented sunscreens, watch for the subtle floral or fruity fragrances from fabric softeners and dryer sheets.

Have Cold Hands

Mosquitoes are attracted by a particular temperature range. The exact temperature depends on the type of mosquito. Many mosquitoes are attracted to the slightly cooler temperatures of the extremities.

Perspire, Swim, or Play in the Sprinkler

Mosquitoes are attracted by perspiration because of the chemicals it contains and also because it increases the humidity around your body. Even small amounts of water (e.g., moist plants or mud puddles) will draw mosquitoes. Standing water also allows mosquitoes to reproduce.

I am a veritable mosquito magnet. I wear a lot of black, favor Coppertone™ when outdoors (bloodsuckers seem to love the subtle jasmine scent of that sunscreen), and can be found near the beach or poking at the barbeque, sipping a sports drink or fruity drink. Don't be like me! Or if you are, try one of these natural mosquito repellents.

Thursday, March 25, 2010

For selected people only

Day 2 was considerably busier than day 1 at Analytica 2010. Although final figures will not be released until tomorrow, members of the organisation confirmed during a press breakfast that these looked promising, with day 1 attracting more visitors than the same day in 2008 (for those of you that don’t know this, Analytica is a biannual event).

In terms of product launches, however, the day was quite quiet, with a number of companies presenting “first time shown in Europe” type releases. At Millipore’s booth, for example, I was shown their automated handheld cell counter and some attractive looking water purification kits. At Thermo Fisher Scientific’s I was treated to a whole tour where they showed me their newest products and had demonstrations of their handheld XRF alloy analysers - if you have recently purchased expensive jewellery you may want to go to their booth and check it is really worth every buck - and Raman spectrometers - I can’t help but wonder how long it will be until these are ubiquitous in airports around the globe to check the contents of passenger’s bottles. And to round up the day I also attended a seminar on the Syro Wave, a microwave and parallel peptide synthesiser that Biotage had launched in mid-February and I had not yet had the opportunity to see for myself.

Day 3 was quite short as I only had the morning at the show, which allowed just enough time for a visit to PerkinElmer’s booth, where I was taken for a private preview - “for selected people only”… it is the first time in my life I’ve been called that! - of a new MS system based on the Flexar LC platform that shows much promise and will formally be unveiled on 23 May at ASMS (we’ll keep you posted on this).

And then it was time to come back home. The show is not over until tomorrow but that is it for me until 2012.

This Day in Science History - March 25 - Friedrich Runge

March 25th marks the passing of Friedrich Ferdinand Runge. Runge was a German chemist most famous for discovering caffeine. The discovery process started when Runge was introduced to the German celebrity and poet Johann Wolfgang von Goethe who also had an interest in science. Goethe was visiting a laboratory where Runge was working on plant extracts. The two men struck up a friendship and eventually Goethe entrusted some Arabian mocha beans to Runge to investigate their properties.

Runge eventually isolated bitter white crystals he called koffein that was the active compound in the beans. He moved onto other avenues of chemistry including the invention of the first blue aniline dye made from coal tar and developed the analytical technique known as paper chromatography.

Helium and Sulfur Hexafluoride Voice Demonstrations

You can breathe in helium and sulfur hexafluoride to change the pitch of your voice and illustrate how density affects the speed of sound. Helium is easy to come by... you can pick up a helium-filled balloon at many grocery stores. To make your voice higher, you just exhale air, take a deep breath of helium and talk (or sing, if you're extroverted). While helium is about six times lighter than air, sulfur hexafluoride is about six times more dense. It isn't as easy to find as helium, but you may be able to get some from a specialty gas store that carries oxygen, argon, etc. You can make yourself sound like Barry White asopposed to Alvin of the Chipmunks by doing the exact same thing as you did with the helium.

Neither helium nor sulfur hexafluoride is toxic, but both can make you lightheaded from breathing them instead of air with oxygen, so use common sense. Don't keep breathing either gas. Exhale after breathing them, then take a deep breath of regular air. Incidentally, it is a myth that you have to bend over to expel the dense sulfur hexafluoride gas. Your lungs are more than capable of breathing it out without any exotic posturing. Have fun, but be safe!

Monday, March 22, 2010

Designer Nanomaterials on Demand: Scientists Report Universal Method for Creating Nanoscale Composites

Composites are combinations of materials that produce properties inaccessible in any one material. A classic example of a composite is fiberglass -- plastic fibers woven with glass to add strength to hockey sticks or the hull of a boat. Unlike the well-established techniques for producing fiberglass and other macroscale composites, however, there aren't general schemes available for making nanoscale composites.

Now, researchers at Berkeley Lab's Molecular Foundry, in collaboration with researcher at the University of California, Berkeley, have shown how nanocomposites with desired properties can be designed and fabricated by first assembling nanocrystals and nanorods coated with short organic molecules, called ligands. These ligands are then replaced with clusters of metal chalcogenides, such as copper sulfide. As a result, the clusters link to the nanocrystal or nanorod building blocks and help create a stable nanocomposite. The team has applied this scheme to more than 20 different combinations of materials, including close-packed
nanocrystal spheres for thermoelectric materials and vertically aligned nanorods for solar cells.

Early Galaxy Went Through 'Teenage Growth Spurt,' Scientists Say

Scientists have found a massive galaxy in the early Universe creating stars like our sun up to 100 times faster than the modern-day Milky Way.

The team of international researchers, led by Durham University, described the finding as like seeing "a teenager going through a growth spurt."

Due to the amount of time it takes light to reach Earth the scientists observed the galaxy as it would have appeared 10 billion years ago -- just three billion years after the Big Bang.

They found four discrete star-forming regions within the galaxy known as SMM J2135-0102. Each regionwas more than 100 times brighter than star-forming regions in the Milky Way, such as the Orion Nebula.

They say their results, published online in the journal Nature, suggest that star formation was more rapid and vigorous in the early Universe as galaxies went through periods of huge growth.

Incorporating Biofunctionality Into Nanomaterials for Medical, Environmental Devices

A team led by researchers from North Carolina State University has published a paper that describes the use of a technique called atomic layer deposition to incorporate "biological functionality" into complex nanomaterials, which could lead to a new generation of medical and environmental health applications. For example, the researchers show how the technology can be used to develop effective, low-cost water purification devices that could be used in developing countries.

This Day in Science History - March 22 - Robert Millikan

March 22nd is Robert Millikan's birthday. Millikan was an American physicist best known for his famous oil drop experiment. The experiment was designed to measure the charge of the electron. The value for the electron charge is one of the fundamental physical constants and the experiment is a staple of university physics students.

Millikan Oil Drop Experiment

Determining the Electron Charge by the Millikan Oil Drop Experiment

Millikan's oil drop experiment measured the charge of the electron.
How the Oil Drop Experiment Worked

The original experiment was performed in 1909 by Robert Millikan and Harvey Fletcher by balancing the downward gravitational force and the upward electrical and buoyant forces of charged oil droplets suspended between two metal plates. The mass of the droplets and the density of the oil was known, so the gravitational and buoyant forces could be calculated from the measured radii of the oil drops. Since the electric field was known, the charge on the oil drops could be determined when the drops were held at equilibrium. The value for the charge was calculated for many droplets.

Did You Know Bananas Glow?

You find out some interesting things when you leave a black light lying around on the kitchen counter. If you read my blog, you already know bananas are slightly radioactive, but did you know the areas around the spots of ripe bananas glows blue under ultraviolet light? Now you do! If you want to check out other household items for a fluorescent glow, I have a list of things that glow under black light. If you are aware of anything I've missed, be sure to post a reply and I'll take a picture/add it to the list.

Sunday, March 21, 2010

More cold water poured on ocean fertilisation

The latest expedition to the Southern Ocean to test the theory that fertilising the ocean combat climate change has concluded that the process sucks negligible amounts of CO2 from the atmosphere.

The theory goes that sprinkling iron into areas of the ocean lacking in the metal will stimulate the growth of algae, which will absorb CO2 from the air as they grow and then carry some of this greenhouse gas to the depths of the ocean when they die.

The German-Indian Lohafex project is the latest expedition to test out the theory in practice. The team found that dumping six tonnes of iron into the ocean did indeed boost algal growth - but that within two weeks the algae were being eaten by a voracious band of tiny crustaceans called copepods, drastically cutting the amount of carbon captured.

These results are just the latest to show that a process that at first glance appears relatively simple is actually far from it. Previous studies - including most recently an investigation into the effects of natural iron fertilisation, where the metal is washed from land into the ocean - have produced conflicting data as to how much extra carbon might be captured.

Pfizer licenses actives to Tocris and Sigma-Aldrich

Pfizer is licensing around 100 of its small molecule compounds to Bristol, UK-based Tocris Bioscience and St Louis, US-based Sigma-Aldrich. Under the agreements, unformulated patented and approved drug molecules such as atorvastatin, sildenafil and sunitinib will be sold for use in pre-clinical research studies. In addition, a number of Pfizer’s literature compounds that have not progressed from development to clinical use will also be offered for sale.

Laurence Ede, Tocris’s managing director, told Chemistry World that the announcement continued the considerable momentum that the company had seen throughout 2009 despite the widespread economic doom and gloom. That momentum saw the company’s sales increase 17 per cent compared to 2008, with sales of new products introduced in 2009 surpassing even 2008’s record levels.

Lilly warehouse hit by thieves

Eli Lilly has fallen foul of one of the largest pharmaceutical heists ever. On Sunday March 21, thieves stole around $75 million of prescription drugs from a warehouse in Connecticut, US. The warehouse contained a range of antidepressant and antipsychotic drugs including Prozac (fluoxetine), Cymbalta (duloxetine), and Zyprexa (olanzapine).

According to media reports, the thieves cut a hole in the roof of the warehouse, before sliding down a rope into the warehouse. The company is working with the US Food and Drug Administration’s (FDA’s) Office of Criminal Investigations, and other law enforcement officials, to recover the stolen drugs.

Digesting chemistry at IUPAC2009

Just a quick blog today as I’ve been out at the Gala dinner here at Glasgow - I had a nice chat with Ben Feringa, who gave a stonking plenary lecture this evening. The man is a genius - he was talking about his group’s work in nanomachinery, making molecular switches, rotors and even molecules that can ’swim’ across surfaces. He made the very interesting point that most chemistry within a cell involves some kind of motor molecule at some stage, whereas none of the chemistry we do in flasks is controlled that way.

This Day in Science History - March 21 - Jean Baptiste Fourier

March 21th is Jean Baptiste Fourier's birthday. Fourier was a French mathematical physicist who is best known for a method to express a periodic function into a sum of simple sine and cosine expressions. This process is used extensively in optics, quantum mechanics, acoustics and electrical engineering.

He was also the first to describe what has become known as the "greenhouse effect". He described a theory where the atmosphere served to heat the surface of a planet by slowing heat loss.

Happy Birthday Fourier! Find out what else occurred on this day in science history

Make Microwave S'mores with Easter Peeps

Easter is two weeks from today on April 4th. It's time to use those Peeps because you know they'll be rock-hard before Easter. I realize a lot of people love Peeps (Easter treat traditionally found in yellow chick form, though other colors and shapes exist), but I always relegated them to the 'not food' category of Easter candy. That was before I learned how to eat them with chocolate.

The recipe is easy and fun. Take a graham cracker, set a Peep on it, put a couple of Hershey's Kisses™ on another cracker, pop them in the microwave, and nuke them until the Peep has expanded so it looks like it's ready to explode (20 seconds seems good). Smush the Peep side and the Kiss side together, and enjoy!

Savannah's Nuclear Bomb is holding a meeting in Savannah this weekend so I suspect my coworkers would be interested to know that there is a live nuclear bomb off the Georgia coast. In February 1958 a B-47 bomber on a training mission out of Homestead Air Force Base in Florida had a collision with an F-86. The pilot of the F-86 parachuted to safety and the fighter jet crashed. The B-47 also sustained damage. The crew requested and received permission to jettison the 7,600 pound Mark 15 bomb it was carrying so that the aircraft could more safely land at Hunter Air Force Base.

When Is Earth Day?

If you've been confused about the answer to this question, it is because Earth Day could fall on either of two days, depending on your preference for when you want to observe it. Some people celebrate Earth Day on the first day of Spring (on the vernal equinox, which falls on March 20, 2010) while others observe Earth Day on April 22. In either case, the purpose of the day is to inspire appreciation for the earth's environment and awareness of issues that threaten it.

Balance an Egg on the Equinox

Saturday, March 20, 2010 is the vernal equinox, which marks the first day of spring in the northern hemisphere. Are you familiar with the urban legend that it's easier to balance an egg on end on the equinox than on other days of the year? Test it and see! This vernal equinox one of the two times during the year when the sun crosses the celestial equator and the spin axis of the Earth points 90 degrees away from the sun. Why should this affect your ability to balance an egg on end? The premise is that aligning the gravitational pull of the Sun with that from the center of the Earth should somehow make it easier to balance any object.

Test the Hypothesis Yourself

Take a carton of eggs and try balancing the eggs on end today. Can you stand any of them up (without resorting to tricks like putting salt under the eggs)? Can you stand eggs on their small ends as well as their large ends? Keep track of your results and repeat the process on the equinox. Do you note any differences? A simple hypothesis to test is: Eggs can only be balanced on-end on the equinox. If you can balance an egg today, you've disproven the hypothesis. It's that easy!

One thing I find neat about egg-balancing is that a balanced egg will hold its position until a vibration knocks it down. How long can you keep an egg standing?

Thursday, March 11, 2010

MARCH 11-Science History

1950 - Arthur Jeffrey Dempster died.

Dempster was a Canadian-American physicist who designed and built the first mass spectrometer. Mass spectrometers are used to separate a sample's components by mass. He later used this device to discover the uranium isotope U-235, the main isotope used in atomic bombs.

1920 - Nicolaas Bloembergen was born.

Bloembergen is a Dutch-American physicist who shares half the 1981 Nobel Prize in Physics with Arthur Schawlow for the development of laser spectroscopy. Kai Siegbahn's research into the development of electron spectroscopy earned him the other half of the prize.

1892 - Archibald Scott Couper died.

James Irvine/Journal of Chemical Education (1930)Couper was a Scottish chemist who described the methods carbon atoms could bond together to form large molecules. He was also the first to describe molecules by element symbols connected by dashes to represent the bonds between the atoms.

1818 - Henri-Étienne Sainte-Claire Deville was born.

Deville was a French chemist who synthesized toluene and anhydrous nitric acid. He also developed the first economical process to produce aluminum.

1811 - Urbain Le Verrier was born.

Verrier was a French mathematician who predicted the existence of Neptune based on the irregularities of the orbit of Uranus. His calculations were used to discover Neptune within 1° of his predicted position. He also proposed the existence of a planet Vulcan inside the orbit of Mercury to explain Mercury's irregular orbit.

This Day in Science History - March 11 - Archibald Scott Couper

March 11th marks the passing of Archibald Scott Couper. Couper was a Scottish chemist who discovered carbon atoms were tetravalent and could form long chain molecules. Prior to this discovery, molecules were believed to possess one central atom, but the structures of many organic compounds could not be explained by this theory.

Couper passed his paper to Charles Adolphe Wurtz to present at the French Academy of Sciences. Unfortunately, Wurtz procrastinated on passing the paper to the Academy and Couper lost priority to German chemist, August Kerkule who also discovered carbon could form bonds and determined the ring structure of benzene. Couper did not take the loss well and never published a scientific paper for the rest of his life.

One lasting contribution Couper gave to chemistry was the way chemical structures are drawn. He was the the first to draw structures where element symbols were connected by lines that represent the bonds between them. Find out what else occurred on this day in science history.

Make Sugar & String Easter Eggs

Here's a fun Easter project for you: crystallize sugar onto string to make an Easter egg basket or a special holiday decoration. The project is similar to growing rock candy crystals except these sugar crystals form much more quickly and are used to form a construction material rather than a tasty crystal treat.

Transcript: How to Make Rock Candy

Hi, I'm Dr. Anne Helmenstine for Have you seen brightly colored rock candy in a store or used to sweeten a drink? Rock candy is simply sugar crystals. I'm going to show you how you can make rock candy yourself, in any color or flavor you like. Are you ready? Let's get started.

Rock Candy Ingredients

The only two ingredients you need for rock candy are sugar and water, though you can add food coloring and flavoring if you want colored and flavored crystals.

Wednesday, March 10, 2010

This Day in Science History - March 10 - Jeremias Richter

March 10th is Jeremias Benjamin Richter's birthday. Richter was a German chemist who introduced the term stoichiometry to chemistry. He noticed the ratio of reactants by weight used in a chemical reaction was always the same. This lead to the law of equivalent or multiple proportions. This discovery was one of the first steps towards a new atomic model of chemical reactions.

Stoichiometry and balancing chemical equations are basic principles learned early in chemistry. Find out how to balance chemical equations or test your knowledge of stoichiometry and find out what else occurred on

Disposable Toilet Turns Human Waste into Fertilizer

Did you know about 2.6 billion people (~40% of the world's population) do not have access to a toilet? Although this is a problem you hopefully don't encounter, it is a major health concern since untreated human feces contaminate the water supply and cause deaths from diarrhea. A Swedish company has a developed a new disposable toilet that it believes will help combat this problem by providing toilets to people at a price point they may be able to afford.

The Peepoo is a biodegradable plastic bag that contains an inner gauze that has been coated with a film of urea. A person uses the Peepoo, ties up the bag, and then buries it. According to a New York Times article, the urea crystals kill the pathogens and break the waste into a safe fertilizer. The bags will sell for around 2-3 cents, which is about the same cost as an ordinary plastic bag. Anders Wilhelmson, inventor of the Peepoo, has tested the bags in India and Kenya, where slum dwellers dispose of waste by collecting it in a plastic bag and flinging it elsewhere. Research indicates there is sufficient space to bury the urea-lined bags even in urban areas. While it may seem strange that such a simple application of chemistry could have such a major impact on so many people, the Peepoo may be just such an invention.