19 K 39.09831

Potassium

ALKALI METAL

Phase: Solid

Discovered: Humphry Davy

Block: S

Summary

Potassium is a chemical element with symbol K (derived from Neo-Latin, kalium) and atomic number 19. It was first isolated from potash, the ashes of plants, from which its name is derived. In the Periodic table, potassium is one of seven elements in column (group) 1 (alkali metals):they all have a single valence electron in their outer electron shell, which they readily give up to create an atom with a positive charge - a cation, and combine with anions to form salts.

Appearance: silvery gray

Source: Wikipedia

Physical Properties

Atomic Mass 39.09831 u

Density 0.862 g/cm³

Melting Point 336.7 K

Boiling Point 1032 K

Molar Heat 29.6 J/(mol·K)

Electron Affinity 48.383 kJ/mol

Ionization Energies

1^st: 418.8 kJ/mol

2^nd: 3052 kJ/mol

3^rd: 4420 kJ/mol

4^th: 5877 kJ/mol

5^th: 7975 kJ/mol

6^th: 9590 kJ/mol

7^th: 11343 kJ/mol

8^th: 14944 kJ/mol

9^th: 16963.7 kJ/mol

10^th: 48610 kJ/mol

11^th: 54490 kJ/mol

12^th: 60730 kJ/mol

13^th: 68950 kJ/mol

14^th: 75900 kJ/mol

15^th: 83080 kJ/mol

16^th: 93400 kJ/mol

17^th: 99710 kJ/mol

18^th: 444880 kJ/mol

19^th: 476063 kJ/mol