Krypton (Kr) » Innovachem

Isotope	Z(p)	N(n)	Atomic Mass	Natural Abundance	Enrichment Level	Chemical Form
Kr-78	36	42	77.92039	0.35%	99.90%	Gas
Kr-80	36	44	79.916379	2.25%	99.90%	Gas
Kr-82	36	46	81.913485	11.60%	99.90%	Gas
Kr-83	36	47	82.914137	11.50%	99.90%	Gas
Kr-84	36	48	83.911508	57.00%	99.90%	Gas
Kr-86	36	50	85.910615	17.30%	99.90%	Gas

Name	Krypton
Symbol	Kr
Atomic number	36
Atomic weight	83.30
Standard state	Gas at 298 °K
CAS Registry ID	7439-90-9
Group in periodic table	18
Group name	Noble gas
Period in periodic table	4
Block in periodic table	p-block
Color	Colorless
Classification	Nonmetallic
Melting point	-157.36 °C
Boiling point	-153.22 °C
Thermal conductivity	0.00943 W/(m·K)
Electronegativity	3.00
Heat of vaporization	9.02 kJ·mol^-1
Heat of fusion	1.64 kJ·mol^-1
Density of gas	.0037 g/cm³
Density of liquid	No data available
Density of solid	2.16 g/cm³
Electron configuration	[Ar]3d¹⁰4s²4p⁶
First ionization potential	13.999 volts
Oxidation state	0 (an uncommon oxidation state +2 exists for its difluoride)
Critical temperature	-63.7 ºC
Critical pressure	54.30 atm
Critical density	0.908 g/L