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Chemical & Physical Properties   Krypton Atomic Number: 36 Symbol: Kr Atomic Weight: 83.80 Discovery: Sir William Ramsey, M.W. Travers, 1898 (Great Britain) Electron Configuration: [Ar] 4s 2 3d 10 4p 6 Word Origin: Greek kryptos : hidden Isotopes: There are 30 known isotopes of krypton ranging from Kr-69 to Kr-100. There are 6 stable isotopes: Kr-78 (0.35% abundance), Kr-80 (2.28% abundance), Kr-82 (11.58% abundance), Kr-83 (11.49% abundance), Kr-84 (57.00% abundance), and Kr-86 (17.30% abundance). Element Classification: Inert Gas

Chemical & Physical Properties of Argon   Argon Atomic Number: 18 Symbol: Ar Atomic Weight: 39.948 Discovery: Sir William Ramsay, Baron Rayleigh, 1894 (Scotland) Electron Configuration: [Ne] 3s 2 3p 6 Word Origin: Greek: argos : inactive Isotopes: There are 22 known isotopes of argon ranging from Ar-31 to Ar-51 and Ar-53. Natural argon is a mixture of three stable isotopes: Ar-36 (0.34%), Ar-38 (0.06%), Ar-40 (99.6%). Ar-39 (half-life = 269 yrs) is to determine the age of ice cores, ground water and igneous rocks. Properties: Argon has a freezing point of -189.2°C, boiling point of -185.7°C, and density of 1.7837 g/l. Argon is considered to be a noble or inert gas and does not form true chemical compounds, although it does form a hydrate with a dissociation pressure of 105 atm at 0°C. Ion molecules of argon have been observed, including (ArKr) + , (ArXe) + , and (NeAr) + . Argon forms a clathrate with b hydroquinone, whi...

Neon Atomic Number: 10 Symbol: Ne Atomic Weight: 20.1797 Discovery: Sir William Ramsey, M.W. Travers 1898 (England) Electron Configuration: [He]2s 2 2p 6 Word Origin: Greek neos : new Isotopes: Natural neon is a mix of three isotopes. Five other unstable isotopes of neon are known. Neon Properties: The melting point of neon is -248.67°C, boiling point is -246.048°C (1 atm), density of gas is 0.89990 g/l (1 atm, 0°C), density of liquid at b.p. is 1.207 g/cm 3 , and valence is 0. Neon is very inert, but it does form some compounds, such as with fluorine. The following ions are known: Ne + , (NeAr) + , (NeH) + , (HeNe) + . Neon is known to form an unstable hydrate. Neon plasma glows reddish orange. The discharge of neon is the most intense of the rare gases at ordinary currents and voltages.

Helium Helium Atomic Number: 2 Helium Symbol: He Helium Atomic Weight: 4.002602(2) Helium Discovery: Janssen, 1868, some sources say Sir William Ramsey, Nils Langet, P.T. Cleve 1895 Helium Electron Configuration: 1s 2 Word Origin: Greek: helios, sun. Helium was first detected as a new spectral line during a solar eclipse. Isotopes: 7 isotopes of helium are known. Properties: Helium is a very light, inert, colorless gas. Helium has the lowest melting point of any element. It is the only liquid that cannot be solidified by lowering the temperature. It remains liquid down to absolute zero at ordinary pressures, but can be solidified by increasing the pressure. The specific heat of helium gas is unusually high. The density of helium vapor at the normal boiling point is also very high, with the vapor expanding greatly when heated to room temperature. Although helium normally has a valence of zero, it has a weak tendency to combine with certain othe...

January 18 th is Edward Frankland's birthday. Frankland was an English chemist who pioneered the idea of valency. He theorized the an element could combine with a limited selection of other elements and established the field of structural chemistry. Together with Joseph Lockyer, Frankland discovered the only element to be discovered outside of Earth before it was discovered terrestrially. Both men were investigating the spectrum given off by the sun when they found a series of lines that did not correspond to any known elements. They named their discovery "helium" after the Sun, or Helios. Their discovery coincided with French astronomer Pierre Janssen solar eclipse discovery of helium. Helium was only found in the spectra of stars and nebulae but never on Earth. It would take another 30 years before helium was detected in an ore of uranium by Swedish chemists Per Teodor Cleve and Nils Langlet. Find out what else occurred on this day in science history.

Once upon a time on a high school field trip, my class visited a magic shop, where we got some disappearing ink. We had great fun spritzing each other with the dark blue ink, which became invisble after a few seconds of exposure in the air. The teacher who was our chaperone wasn't quite as amused as we were when her silk blouse was 'stained' with the ink. The color disappeared, but a visible spot remained from the liquid on a dry-clean-only fabric. Therefore, these instructions for disappearing ink are presented to you with the advice that you don't spray the ink onto anything that can't survive washing. Otherwise, disappearing ink is easy to make and can be used to demonstrate acid-base indicators.

Here's a bit of chemistry you may want to know if you're ever pulled over and given a breath test: dieting can cause you to test positive for a DUI breathalyzer. According to the National Substance Abuse Index, many breathalyzers measure methyl groups, which are a product of alcohol metabolism, rather than the presence of ethyl alcohol itself. This means that any chemical exposure or metabolic process that produces methyl groups may produce a false positive breathalyzer result. High protein, low carbohydrate diets, including the Atkins diet, causes your body to produce ketones or acetone, which the test reads as a possible metabolite from drinking alcohol. Other causes of false positive DUI breathalyzer tests include absorption of chemicals from pumping gas, inhaling glue fumes, handling glue or medical conditions including hyperglycemia. In-car ignition interlock devices may test for alcohol, but non-specifically, meaning any alcohol will register a positive re...

January 17 th marks the passing of two people, William Pickering and Clyde Tombaugh, who were important to the discovery of the dwarf planet, Pluto. William Pickering was an American astronomer who believed there was a planet outside the orbit of Neptune that caused the unusual shape of the orbit of Neptune and Uranus. He was instrumental in the establishment of Lowell observatory in Flagstaff, Arizona with Percival Lowell to search for this "Planet X". Powell spent the rest of his life searching, even photographing Pluto on film twice without recognizing the planet. Clyde Tombaugh joined the staff at Lowell Observatory and was given the task of taking systematic photographs of portions of the night sky on two nights one week apart. He would load the images in a device called a blink comparator that rapidly switches the two photographs. This allowed Tombaugh to detect slight differences between the photographs which would suggest movement. He found a change fr...

Question: What Are the Ingredients in Rubbing Alcohol? Answer: One of the types of alcohol you can buy over the counter is rubbing alcohol, which is used for disinfection and may be applied to the skin to produce a cooling effect. Do you know the chemical composition of rubbing alcohol? It is a mixture of denatured alcohol, water and agents added to make the alcohol unpalatable to drink and sometimes colorants. There are two common types of rubbing alcohol. Isopropyl Rubbing Alcohol Most rubbing alcohol is made from isopropyl alcohol or isopropanol in water. It is common to find isopropyl rubbing alcohol at concentrations from 68% alcohol in water up to 99% alcohol in water. The 70% rubbing alcohol is highly effective as a disinfectant. Additives make this alcohol bitter-tasting, to try to prevent people from drinking it. Isopropyl alcohol is toxic, in part because the body metabolizes it into acetone. Drinking this alcohol can cause headache, dizziness, nausea, vo...

Here's a fun chemistry demonstration that's perfect for Valentine's Day or to illustrate an oxidation-reduction reaction. The Vanishing Valentine involves shaking a solution, causing it to turn pink. If the pink Valentine solution is left undisturbed, it will become colorless. The color change cycle can be repeated several times. It is caused by the oxidation and reduction of resazurin. an indicator that is pink or colorless depending on its oxidation state. Vanishing Valentine Materials 100 ml of a 0.133 M dextrose solution (C 6 H 12 O 6 ) 100 ml of a 1.0 M sodium hydroxide solution (NaOH) 1 ml of a 0.1% resazurin solution a 250-ml or 500 ml Erlenmeyer flask or separatory funnel (resembles a heart) stopper for the flask dropper or pipette Prepare the Solutions Dextrose Solution: Dissolve 2.4 g of dextrose in distilled or deionized water to make 100 ml of solution. Sodium Hydroxide Solution: Prepare the 1.0 M sodium hydroxide solution by dissolvin...

Although it may look complicated to make, rock candy is simply made of crystallized sugar. In this video, learn how to make this classic treat

Chemistry is the study of matter and the interactions between different types of matter and energy. The fundamental building block of matter is the atom. An atom consists of three main parts: protons, neutrons, and electrons. Protons have a positive electrical charge. Neutrons have no electrical charge. Electrons have a negative electrical charge. Protons and neutrons are found together in what is called the nucleus of the atom. Electrons circle around nucleus. Chemical reactions involve interactions between the electrons of one atom and the electrons of another atom. Atoms which have different amounts of electrons and protons have a positive or negative electrical charge and are called ions. When atoms bond together, they can make larger building blocks of matter called molecules.

The element boron consists of two isotopes, 10 5 B and 11 5 B. Their masses, based on the carbon scale, are 10.01 and 11.01, respectively. The abundance of 10 5 B is 20.0%. What is the atomic abundance of and the abundance of 11 5 B? Solution The percentages of multiple isotopes must add up to 100%. Since boron only has two isotopes, the abundance of one must be 100.0 - the abundance of the other. abundance of 11 5 B = 100.0 - abundance of 10 5 B abundance of 11 5 B = 100.0 - 20.0 abundance of 11 5 B = 80.0 Answer The atomic abundance of 11 5 B is 80%

January 15 th is Artturi Ilmari Virtanen's birthday. Virtanen was a Finnish biochemist who invented the AIV (his initials) fodder technique to prevent spoilage in stored green silage. Storing green plant fodder during long winters was always difficult since by the end of winter, it would ferment and be rendered inedible and possibly result in starvation. Virtanen noticed the process of fermentation would cease when a particular acidity was reached. He prepared a solution of dilute hydrochloric or sulfuric acid and added it to the stored fodder. The fodder remained fresh and did not affect its nutritive value. This discovery greatly changed the way agricultural fodder is stored. It also earned Virtanen the 1945 Nobel Prize in Chemistry. 1997 - Kenneth Vivian Thimann died. Thimann was an English-American plant physiologist who isolated the plant growth hormone auxin. Auxin promotes cell elongation, formation of roots, and growth of buds in plants. Thimann's disc...

Thames and Kosmos produces several science kits, including multiple chemistry sets. The Chem C3000 is their ultimate chemistry kit. Chemistry education and labs have moved toward computer simulations and 'safe' chemicals, so it's actually quite hard to find a kit that offers the types of hands-on experimentation that set the standard for chemistry labs in the past. The Chem 3000 is one of the few chemistry kits on the market today that contains chemicals and equipment necessary to perform over 350 high school / advanced chemistry experiments. This is the most popular chemistry kit for home school chemistry and self-teaching. Description This is the ultimate chemistry kit ! Thames & Kosmos Chem C3000 kit contains everything in their Chem C1000 and Chem C2000 kits, plus more chemicals and equipment. You'll be able to perform over 350 chemistry experiments. The kit comes in a box containing two styrofoam packing trays. The company reserves the rig...

Thames and Kosmos makes several serious chemistry kits that include glassware, chemicals, and detailed workbooks that explain how to perform experiments. These kits are perfect for anyone looking for the full chemistry lab experience, including students seeking to satisfy home school requirements. The Chem C1000 and Chem C2000 kits offer numerous experiments at economical prices. The Chem C3000 kit is an exceptional complete set that essentially sets you up with a home chemistry lab and chemicals to perform hundreds of experiments. Although Thames and Kosmos makes high-end advanced sets, the company also makes introductory kits for kids.

Chemistry kits are a fun way to introduce kids to hands-on chemistry, plus they are a must-have if you're learning chemistry from home. I've tried many kits over the years. Some were duds, while others offered hours of engagement, reliable results, and clear instructions. Here's a short list of my favorite sets, grouped by experience level and topic

You know what metals are. You have iron in your blood, might wear a gold or silver ring on your finger, and eat using stainless steel utensils. Yet, how good are you at metal trivia? What interesting facts about metals do you know?... Take the quiz

January 14 th marks the passing of Cato Guldberg. Cato and Peter Waage were Norwegian chemists who discovered the chemistry law of mass action. The law of mass action relates the rate of a reaction to the concentration of the reactants. They had an interesting journey to get their work recognized and is a lesson in getting published in the 'right' scientific journals. They initially published their findings in a Norwegian scientific journal and consequently, gained very little recognition for their research. They republished their work in a French journal which did not attract any more attention. Their work remained obscure until German chemist, Wilhelm Ostwald published an article that mentioned the law and proved their results with experiments of his own. Dutch chemist Jacobus van't Hoff derived his kinetics equations in 1888 and received credit for the discovery, they republished again in a German journal and finally got the recognition for their work. 20...

Technically, all food is slightly radioactiv e. This is because all food and other organic molecules contain carbon, which naturally exists as a mixture of isotopes, including radioactive carbon-14. That's the basis for carbon dating , used to identify the age of fossils. However, some foods emit much more radiation than others. Here's a look at 10 naturally radioactive foods and how much radiation you get from them. 1. Brazil Nuts If there was an award for "Most Radioactive Food," it would go to Brazil nuts. Brazil nuts contain high levels of two radioactive elements: radium and potassium. Potassium is good for you, used in many biochemical reactions, and one of the reasons why the human body is itself slightly radioactive. Radium occurs in the ground where the trees grow and is absorbed by the plant's root system. Brazil nuts emit over  6,600 pCi/kg of radiation. Most of that radiation passes harmlessly through the body, plus the high levels...

Some of the foods you eat are naturally radioactive. Sometimes the radiation comes from isotopes that a plant absorbs as it's growing, while other foods are radioactive because they contain high levels of elements that exist as a mixture of isotopes. Pictured here is a common food that emits radiation.   Question: What Is Radioactivity? What is Radiation?    Unstable atomic nuclei will spontaneously decompose to form nuclei with a higher stability. The decomposition process is called radioactivity. The energy and particles which are released during the decomposition process are called radiation. When unstable nuclei decompose in nature, the process is referred to as natural radioactivity. When the unstable nuclei are prepared in the laboratory, the decomposition is called induced radioactivity. Answer: There are three major types of natural radioactivity: Alpha Radiation Alpha radiation consists of a stream of positively charged particles, called a...

One of the most common calculations you'll be expected to perform on data is standard deviation. It is so important that most calculators have a button for it! However, you should be able to do this calculation by hand, plus you need to know which standard deviation formula to apply. That's right! There is more than one. Apply the population standard deviation formula when you are analyzing a complete set of data. This may be data from all the members of a class or all the trials of an experiment. Apply the sample standard deviation formula when you are analyzing a sample or set of samples from a larger population. Note that the sample standard deviation formula contains a correction factor, called Bessel's correction, that expresses increased uncertainty in how reliable your data is. Why would you do this? The correction factor helps form a more realistic prediction of what you could expect from future testing. It is helpful when you can't get data from ...

Michael de Podesta studied Physics at Sussex University, receiving his B.Sc. in 1981 and was awarded a D.Phil. in 1985. After postdoctoral work at Bristol University he was appointed a lecturer at the University of London in 1987 and joined NPL in 2000. Since then he has specialised in temperature measurements of all kinds and has recently completed the most accurate measurement of temperature in history. Michael is a chartered physicist, a member of the Institute of Physics and in 2009 he was awarded an MBE for Services to Science.   The webinar begins by asking the question “Why is the Earth’s surface the temperature it is?”. The answer to this question is not contentious but is often not fully appreciated. This understanding then forms the basis of an analysis of why scientists are concerned that human emissions of carbon dioxide are causing Global Warming.

Do you need to learn chemistry fast? Here is how you do it! Plan To Learn Chemistry Fast The first step is to determine exactly how long you have to learn chemistry. You'll need a lot more discipline to learn chemistry in a day compared with a week or a month. Also, keep in mind you won't have great retention if you cram chemistry in a day or a week. Ideally you want a month or longer to master any course. If you do end up cramming chemistry, expect to review the material if you need to apply it to a higher level chemistry course or remember it for a test further down the road. A Word About Chemistry Lab If you can do labwork, that's fantastic, because the hands-on learning will reinforce the concepts. However, labs take time, so most likely you'll miss this segment. Keep in mind labs are required for some situations. For example, you have to document labwork for AP Chemistry and many online courses. If you are doing labs, check how long they take ...

pH is a measure of hydrogen ion concentration or [H + ] in an aqueous solution. It is a useful gauge of the acidity of a solution. Yet, do you know why we use the symbol "pH" or what it stands for? Have you ever wondered what pH stands for or where the term originated? Here is the answer to the question and a look at the history of the pH scale. Question: What Does pH Stand For?     Answer: pH is the negative log of hydrogen ion concentration in a water-based solution. The term "pH" was first described by Danish biochemist Søren Peter Lauritz Sørensen in 1909. pH is an abbreviation for "power of hydrogen" where "p" is short for the German word for power, potenz and H is the element symbol for hydrogen. The H is capitalized because it is standard to capitalize element symbols. The abbreviation also works in French, with pouvoir hydrogen translating as "the power of hydrogen". Logarithmic Scale The pH scale is a l...

January 13 th marks the passing of Paul Niggli. Niggli was a Swiss mineralogist who was a pioneer of x-ray crystallography. He developed the mathematical system of space groups that defined 230 different atom arrangements based on x-ray diffraction patterns. X-ray crystallography works by shining x-ray radiation through a crystal structure and detecting the interference pattern generated by the gaps between individual atoms. This information can tell you the position of atoms in a crystal, the width of atomic bonds, and even the size of the atoms themselves. All this information can give detailed help in determining the structure of a molecule. All that is really needed is a pure sample that can be crystallized. 1927 - Sydney Brenner was born. Brenner is a South African biologist who shares the 2002 Nobel Prize in Medicine with H. Robert Horvitz and John Sulston for their discoveries of how genes regulate organ development and cell death. His research centered on th...

Mix two clear solutions, wait, and watch the liquid turn to gold! This is a simple alchemy project or chemistry demonstration, based on early attempts to make gold from base metals.     Liquid Gold Materials Solution A 1 gram sodium arsenite 50 ml water 5.5 ml glacial acetic acid Prepare Solution A by stirring the sodium arsenite into the water. Mix the glacial acetic acid into this solution. Solution B 10 grams sodium thiosulfate (photographer hypo) 50 ml water Prepare Solution B by stirring the sodium thiosulfate into the water. Let's Make Liquid Gold! Pour one solution into the other. The clear solution will turn gold after about 30 seconds. For dramatic effect, keep track of the time and command the solution to turn into gold. You can even use a magic word, if you like. The Chemistry Behind How It Works There is a delayed reaction between the acid and the sodium thiosulfate to release hydrogen sulfide gas. The hydrogen sulfide reacts in turn ...

One of the quests of the ancient alchemists (and possibly modern ones as well) was to transmute a base material into gold. While it's possible to turn lead into gold using a particle accelerator, alchemists tend to seek chemical reactions that might produce gold. One reaction they explored appeared to turn water into gold. You can try this too, as an interesting experiment or as a memorable chemistry demonstration.

You can obtain pure lithium from a lithium battery. It's an adult-only project and even then, you need to use safety precautions, but it's simple and easy.     Safety Precautions Lithium reacts with moisture and may spontaneously ignite. Don't allow it to come in contact with your skin. Also, cutting into a battery often causes a short circuit, which may produce a fire. While this is not unexpected or problematic, it does mean you need to perform this procedure on a fire-safe surface such as concrete, preferably outdoors. Eye and skin protection is a must. Materials You want a new battery for this project since the lithium can be extracted as a relatively uncorroded metal foil. If you use a used battery you'll get a product that might be better for making colored fire, but it will be impure and fragile. New Lithium Battery (e.g., AA or 9V lithium battery) Safety Glasses or Goggles Gloves Insulated Wirecutters and Pliers Procedure Basically yo...

While you may know Adderall and other amphetamines can cause psychosis (in addition to other effects), were you aware other stimulants can cause psychotic behavior, including caffeine? This is called stimulant psychosis and is characterized by: delusions hallucinations disordered thinking catatonia (extreme cases) Physical symptoms are those of stimulant overdose, which you can get without suffering stimulant psychosis: nausea diarrhea hypertension (high blood pressure) rapid breathing hyperthermia (elevated temperature) sleep deprivation tremor Drugs that are known to cause stimulant psychosis include: amphetamines methylphenidate (Ritalin) cocaine caffeine The effect typically occurs at high doses or from chronic use. Often it is temporary, although sometimes recovery is incomplete. In the case of caffeine, psychosis may be related to lack of B-vitamins, nervous system exhaustion, or a pre-existing mental condition. It's somewhat controversial beca...

On January 11, 1922 insulin was used for the first time on a human patient. Leonard Thompson, a 14-year-old diabetic at Toronto General Hospital received an injection of Dr. Banting and Best's recently purified insulin. They had previously tested their hormone on dogs with positive results. Leonard's diabetes seemed to recede but he developed an allergic reaction. This reaction was later traced to an impurity in their sample and a more purified sample was used two weeks later. Leonard survived his previous death sentence of diabetes for another 13 years using insulin until he died from pneumonia at age 27. Dr. Best would later earn the 1923 Nobel Prize in Medicine for this achievement and diabetics everywhere were given a chance at a normal life.

If you've ever been asked to explain why chemistry is important, you may have found it challenging to explain what must seem so obvious to you! If you teach chemistry or are a parent, you're bound to get asked this question. If you're taking chemistry, answering why chemistry is important is a common assignment. Here's my answer and a chance for you to answer the question, too:   Answer: Chemistry has a reputation for being a complicated and boring science, but for the most part, that reputation is undeserved. Fireworks and explosions are based on chemistry, so it's definitely not a boring science. If you take classes in chemistry, you'll apply math and logic, which can make studying chemistry a challenge if you are weak in those areas. However, anyone can understand the basics of how things work... and that's the study of chemistry. In a nutshell, the importance of chemistry is that it explains the world around you. Chemistry Explains... * Cooking...