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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...