DOE/LANL Jurisdiction Fire Danger Rating:

Krypton

83.8

Krypton

Element Stats

Select a temperature unit to update boiling and melting point values.

Physical

Physical Properties
Property	Value	Property	Value
Appearance	Colorless gas. Exhibits a white glow when excited by an electrical discharge.
Classification	Noble Gases	Density	3.749 g/cm³ at STP
Boiling Point	119.93 K	Melting Point	115.78 K

Atomic

Atomic Properties
Property	Value	Property	Value
Atomic Number	36	Atomic Mass	83.7982
Van Der Waals Radius	202	Atomic Radius (empirical)	--

Electronic & Chemical

Electronic and Chemical Properties
Property	Value	Property	Value
Electronegativity	3	Electron Affinity	-96 kJ/mol
Electron Configuration	1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶
Oxidation States	2, 1, 0 (rarely more than 0)
Ionization Energies	Showing 5 of 30 ionization energies. 1350.8 kJ/mol 2350.4 kJ/mol 3565 kJ/mol 5070 kJ/mol 6240 kJ/mol

History

In 1898, chemists William Ramsay and Morris Travers evaporated liquid air, removing all its components. The residue that was left was the noble gas, krypton. This same fractional distillation method helped scientists discover three noble gases in the same year!

In 1960, scientists decided to define a meter using the light from the element krypton-86. They measured the meter as the distance of 1,650,763.73 wavelengths of krypton light in a vacuum, replacing an older definition that used a metal bar. This new way of measuring was much more precise! The krypton-based definition lasted until 1983, when scientists switched again, this time defining a meter as the distance light travels in a vacuum in 1/299,792,458 seconds. This change helped us measure distances even more accurately!

Properties

Like most noble gases, krypton is colorless and odorless. It is characterized by several lines on the emission spectrum (the spectrum of frequencies of electromagnetic radiation). The strongest spectral lines that make up krypton are green and yellow. Solid krypton is white and has a face-centered cubic crystal structure.

Uses

The most popular use of krypton is in light sources—especially in light bulbs for flashlights and cameras. Although krypton is mostly inert, it is reactive enough to combine with fluorine, which creates a useful krypton-fluoride combination used in some lasers.

Krypton is used in nuclear fusion experiments and experimental particle physics. Because krypton is a product of nuclear reactors, it is also used to detect nuclear production.

Compounds

Krypton is mostly nonreactive like its noble gas counterparts, but it does react with fluorine under extreme conditions.

Forms

The krypton we find in the Earth’s atmosphere has five stable isotopes. Krypton also has about 30 unstable isotopes and isomers. An additional isotope, krypton-78, has an extremely long half-life—9.2x10²¹ years! Because the isotope lasts so long before it decays, scientists consider it stable.

Sources

Krypton is one of the noble gases that has remained on Earth since its formation, and we can obtain it from the air by using fractional distillation. The concentration of krypton in the atmosphere is about 1 ppm, but the amount in space is a little more uncertain. Scientists believe there are high amounts of krypton in space based on measurements that use meteoric activity and solar winds.

Fun Facts

It was Krypton that made me Superman, but it's the Earth that makes me human.

In 1949, the Superman comic used Krypton as the name for a fictional planet and the mineral kryptonite—Superman’s greatest weakness. Since then, the fictional version of Krypton has gained more popularity than the real gas.

What's in a name?

Krypton is named after the Greek word kryptos, which means “hidden.” The chemists who first found it in the late 1800s suspected its presence in a sample of liquified air, but had to search for it by boiling off the other elements in the sample.

Safety first!

French chemist Victor Grignard discovered this by accidentally inhaling krypton during an experiment. He was okay, though, and went on to win a Nobel prize for his other work!

DOE/LANL Jurisdiction Fire Danger Rating:

Krypton

83.8

Krypton

Element Stats

Select a temperature unit to update boiling and melting point values.

Physical

Physical Properties
Property	Value	Property	Value
Appearance	Colorless gas. Exhibits a white glow when excited by an electrical discharge.
Classification	Noble Gases	Density	3.749 g/cm³ at STP
Boiling Point	119.93 K	Melting Point	115.78 K

Atomic

Atomic Properties
Property	Value	Property	Value
Atomic Number	36	Atomic Mass	83.7982
Van Der Waals Radius	202	Atomic Radius (empirical)	--

Electronic & Chemical

Electronic and Chemical Properties
Property	Value	Property	Value
Electronegativity	3	Electron Affinity	-96 kJ/mol
Electron Configuration	1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶
Oxidation States	2, 1, 0 (rarely more than 0)
Ionization Energies	Showing 5 of 30 ionization energies. 1350.8 kJ/mol 2350.4 kJ/mol 3565 kJ/mol 5070 kJ/mol 6240 kJ/mol

History

Properties

Uses

Krypton is used in nuclear fusion experiments and experimental particle physics. Because krypton is a product of nuclear reactors, it is also used to detect nuclear production.

Compounds

Krypton is mostly nonreactive like its noble gas counterparts, but it does react with fluorine under extreme conditions.

Forms

Sources

Fun Facts

It was Krypton that made me Superman, but it's the Earth that makes me human.

What's in a name?

Safety first!

French chemist Victor Grignard discovered this by accidentally inhaling krypton during an experiment. He was okay, though, and went on to win a Nobel prize for his other work!