 |
Krypton |
---|
Pronunciation | (KRIP-ton) |
---|
Appearance | colourless gas, exhibitin a whitish glow in a heich electric field |
---|
Standard atomic weight Ar, std(Kr) | 7001837980000000000♠83.798(2)[1] |
---|
Mass number | Kr: |
---|
Krypton in the periodic cairt |
---|
|
Atomic nummer (Z) | 36 |
---|
Group | group 18 (noble gases) |
---|
Period | period 4 |
---|
Block | p-block |
---|
Element category | Noble gas |
---|
Electron confeeguration | [Ar] 3d10 4s2 4p6 |
---|
Electrons per shell | 2, 8, 18, 8 |
---|
Pheesical properties |
---|
Phase at STP | gas |
---|
Meltin pynt | 115.78 K (-157.37 °C, -251.27 °F) |
---|
Bylin pynt | 119.93 K (-153.415 °C, -244.147 °F) |
---|
Density (at STP) | 3.749 g/L |
---|
whan liquid (at b.p.) | 2.413[2] g/cm3 |
---|
Treeple pynt | 115.775 K, 73.53[3] kPa [4] |
---|
Creetical pynt | 209.48 K, 5.525[3] MPa |
---|
Heat o fusion | 1.64 kJ/mol |
---|
Heat o vapourisation | 9.08 kJ/mol |
---|
Molar heat capacity | 5R/2 = 20.786 J/(mol·K) |
---|
Vapour pressur
P (Pa)
|
1
|
10
|
100
|
1 k
|
10 k
|
100 k
|
---|
at T (K)
|
59
|
65
|
74
|
84
|
99
|
120
|
---|
|
Atomic properties |
---|
Oxidation states | 0, +1, +2 (rarely mair nor 0; oxide is unknown) |
---|
Electronegativity | Pauling scale: 3.00 |
---|
Covalent radius | 116±4 pm |
---|
Van der Waals radius | 202 pm |
---|
Spectral lines o krypton |
Ither properties |
---|
Naitural occurrence | Kr: Primordial |
---|
Creestal structur | face-centred cubic (fcc) |
---|
Speed o soond | (gas, 23 °C) 220, (liquid) 1120 m/s |
---|
Thermal conductivity | 9.43×10-3 W/(m·K) |
---|
Magnetic orderin | diamagnetic[5] |
---|
CAS Nummer | 7439-90-9 |
---|
History |
---|
Diskivery | William Ramsay an Morris Travers (1898) |
---|
First isolation | William Ramsay an Morris Travers (1898) |
---|
Main isotopes o krypton |
---|
|
Decay modes in parentheses are predictit, but hae nae yet been observed |
| references |