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, which is 2 in the outermost shell.

Related: electron configuration, the Bohr model, valence electrons.

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.

Strontium: frequently asked questions

What is Strontium?
Strontium (Sr) is the chemical element with atomic number 38. It is a metal: specifically an alkaline earth metal.
What is the atomic number of Strontium?
Strontium's atomic number is 38, which means every Strontium atom has 38 protons in its nucleus.
What is the electron configuration of Strontium?
The electron configuration of Strontium is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 (noble-gas shorthand: [Kr] 5s2). Its electrons are arranged in shells of 2, 8, 18, 8, 2, with 2 in the outermost shell.
Is Strontium a metal or a nonmetal?
Strontium is a metal: specifically an alkaline earth metal.
What group and period is Strontium in?
Strontium is in group 2 and period 5 of the periodic table.
Is Strontium a solid, liquid, or gas?
At room temperature, Strontium is a solid.

Position in the periodic table

Open the interactive periodic table →

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