38 Sr 87.621

Strontium

alkaline earth metal

Properties

Atomic number
38
Atomic mass
87.621 u
Category
alkaline earth metal
Group
2
Period
5
Block
s-block
State (room temp)
Solid
Outer-shell electrons
2
Electronegativity
0.95 (Pauling)
Density
2.64 g/cm³
Melting point
776.85 °C
Boiling point
1376.85 °C

Electron configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s²

Noble-gas shorthand: [Kr] 5s²

Electrons per shell: 2, 8, 18, 8, 2 — that's 2 in the outermost shell.

See how electron configuration is built →

Sr
Bohr model — outer-shell electrons in blue

About Strontium

Strontium 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.

Position in the periodic table

Open the interactive periodic table →

Data compiled from Wikipedia, PubChem, and IUPAC. Source.