Rubidium Yttrium

Strontium (Sr)

From Wikipedia, the free encyclopediaStrontium is a chemical element with symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white or yellowish metallic element that is highly reactive chemically. The metal turns yellow when it is exposed to air.

Strontium in the periodic table

Symbol

Atomic number

Group

Period

Block

Element category

Alkaline Earth Metal

Physical properties

Phase at STP

Solid

Density

2.64 g/cm³

Atomic weight

87.621 u

Melting point

1050 K
776.85 °C
1430.33 °F

Boiling point

1650 K
1376.85 °C
2510.33 °F

Atomic properties

Electronegativity (Pauling Scale)

0.95

Electron affinity

5.023 kJ/mol

Oxidation states

+1, +2
(a strongly basic oxide)

Ionization energies

1	549.5 kJ/mol
2	1064.2 kJ/mol
3	4138 kJ/mol
4	5500 kJ/mol
5	6910 kJ/mol
6	8760 kJ/mol
7	10230 kJ/mol
8	11800 kJ/mol
9	15600 kJ/mol
10	17100 kJ/mol
11	31270 kJ/mol

Electron configuration

Elektronkonfiguration (shorthand)

[Kr] 5s²

Electron configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 5s²

Electrons per shell

2, 8, 18, 8, 2

History

Discovered

1787

Discovered by

William Cruickshank