K - Potassium

In 1807, Humphrey Davy electrolyzed "fused potash" (KOH) to form pure potassium at the cathode. Potassium, also known as kalium, is a soft alkali metal and one of the most active metals known. 

Atomic number - 19 Density g/mL 0 .86
Atomic weight u 39 .0983 Melting point K 336 .35
Bonding radius A 2 .03 Boiling point K 1032
Atomic radius A 2 .77 Heat of vaporization kJ/mol 79 .87
Ionization Potential V 4 .341 Heat of fusion kJ/mol 2 .334
Electronegativity - 0 .82 Specific heat J/gK 0 .75
The oxide is a strong base.
Crystal are body centered cubic.

Electron config. : [Ar] 4s1


 Isotopes of K: Click mass number for decay process, product for element page.


035
190 msec
EC/ECp,11.881
Ar-35/Cl-34
34.988011 		036
342 msec
EC/ECa/ECp,12.805
Ar-36/S-32/Cl-35
35.981293 		037
1.226 sec
EC,6.149 MeV
Ar-37
36.973376 		038
7.636 min
EC,5.913 MeV
Ar-38
37.969080 		038a
923.9 msec
EC,6.043 MeV
Ar-38
37.969219 		039 93.2581%

Stable

38.963706 		040 0.0117%
1.277E+9 yr
B-/EC,1.311
Ca-40/Ar-40
39.963998
041 6.7302%

Stable

40.961825 		042
12.360 hr
B-,3.525 MeV
Ca-42
41.962403 		043
22.3 hr
B-,1.815 MeV
Ca-43
42.960715 		044
22.13 min
B-,5.660 MeV
Ca-44
43.961556 		045
17.3 min
B-,4.204 MeV
Ca-45
44.960699 		046
105 sec
B-,7.716 MeV
Ca-46
45.961976 		047
17.50 sec
B-,6.643 MeV
Ca-47
46.961677
048
6.8 sec
B-/B-n,12.090
Ca-48/Ca-47
47.965512 		049
1.26 sec
B-/B-n,10.970
Ca-49/Ca-48
48.967450 		050
472 msec
B-/B-n,14.200
Ca-50/Ca-49
49.972731 		051
365 msec
B-/B-n,3.560
Ca-51/Ca-50
50.975833 		052
105 msec
B-/B-n,8.020
Ca-52/Ca-51
51.982261 		053
30 msec
B-/B-n,10.280
Ca-53/Ca-52
52.986732 		054
10 msec
B-/B-n,18.000
Ca-54/Ca-53
53.993988
MASS abund.
Halflife
Particle, Energy
Decay Product(s)
Isotopic Mass