Periodic TableAll elementsStrontium
No. 038
Sr
87.62 u
Element · Alkaline Earth

Strontium

Strontium (锶, symbol Sr) is chemical element number 38, an Alkaline Earth in period 5, group 2 of the periodic table, with a standard atomic weight of about 87.62. Soft, silver-yellow metal. Gives fireworks their brilliant red color.

Period 5Group 2[Kr] 5s²

Properties

Atomic number38
SymbolSr
Atomic mass87.62 u
CategoryAlkaline Earth
Period5
Group2
Electron configuration[Kr] 5s²
Electronegativity0.95
Covalent radius195 pm
Density2.64 g/cm³
Melting point1050 K
Boiling point1655 K
DiscoveryWilliam Cruickshank, 1787

Overview

Soft, silver-yellow metal. Gives fireworks their brilliant red color. Strontium (Sr) is an Alkaline Earth with atomic number 38, located in period 5, group 2. As an alkaline-earth metal it is a little less reactive than the alkali metals and occurs in nature mainly within mineral compounds.

Its electron configuration is [Kr] 5s², with 2 electrons in the outer shell, and an electronegativity of about 0.95 (Pauling). Around 25 °C it is usually a solid; it melts near 1050 K (776.9 °C), boils near 1655 K (1381.9 °C), has a density around 2.64 g/cm³.

In industry and daily life it turns up in Pigments / Glass, Medical / Pharma and Research. It was first described by William Cruickshank in 1787. Use the comparison tool to line it up against other elements.

Electron shells

Sr38

Electrons per shell: 2 · 8 · 18 · 8 · 2

Main uses

Hazard

LowNo special hazard flags.

Compounds containing Strontium

No compounds in this knowledge base contain Strontium yet.

Data sources

Atomic mass uses IUPAC (CIAAW) standard atomic weights; the covalent radius is from Cordero et al. (2008). Verify on the RSC Periodic Table, PubChem and Wikipedia. Educational reference only.