Question

Predict the state of matter and the chemical reactivity of Krypton.

Answer 1

Characteristics: Krypton is a colorless, odorless, inert gas. Although it is extremely unreactive krypton can react with the very reactive gas fluorine. A few compounds of krypton have been prepared, including krypton (II) fluoride and krypton clathrates. It has a boiling point of -152.9°C (-243.2°F) and a density of 3.64 grams per liter.

Step-by-step explanation:

Interesting Facts about Krypton

• Between 1960 and 1983, the scientific unit of length, the meter, was defined as 1 650 763.73 wavelengths of krypton-86’s orange-red spectral line. (The meter is now defined as the distance travelled by light in a vacuum during a time interval of 1/299 792 458 of a second.

• From its discovery in 1898 until the 1960s most scientists believed it was impossible to make compounds of krypton, or any other noble gas – although see William Ramsay, above. Krypton difluoride was made in 1963. It is a white, crystalline solid, stable at temperatures below -30 oC.

• Krypton is not very abundant in our planet’s atmosphere: For every krypton atom, there are about 8200 argon atoms, 184 000 oxygen molecules and 685 000 nitrogen molecules.

• Krypton-85 in the atmosphere can be used to detect the presence of otherwise secret nuclear weapons research and production facilities.

• Krypton-fluorine lasers produce pulses with 500 times the power of the entire U.S. electrical grid. Not surprisingly, these pulses are of short duration: four billionths of a second.

Abundance and Isotopes

• Abundance earth’s crust: 100 parts per trillion by weight, 30 parts per trillion by moles

• Abundance solar system: parts per million by weight, parts per million by moles

• Cost, pure: $33 per 100g

• Cost, bulk: $ per 100g

• Source: Krypton is obtained commercially by fractional distillation of liquid air.

• Isotopes: Krypton has 25 isotopes whose half-lives are known, with mass numbers 71 to 95. Naturally occurring krypton is a mixture of six isotopes and they are found in the percentages shown: 78Kr (0.4%), 80Kr (2.3%), 82Kr (11.6%), 83Kr (11.5%), 84Kr (57.0%) and 86Kr (17.3%). The most abundant isotope is 84Kr at 57.0%.