Strontium
alkaline earth metal · period 5 · group 2 (alkaline earth metals) · s-block
Strontium is the chemical element with the symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly chemically reactive.
What the numbers say
At standard temperature and pressure Strontium is a solid, sitting in period 5, group 2 of the s-block.
Its melting point of 1050 K (777 °C) is the 64th highest of the 110 elements with a measured value — mid-range among the elements.
At 2.63 g/cm³ it is the 72nd densest of 96 elements with a quoted density.
Pauling electronegativity is 0.95. Paired with oxygen (3.44) that is a difference of 2.49, which puts the bond predominantly ionic — expect a stable oxide ceramic.
In the solid state it takes a face-centered cubic structure — FCC packing gives 12 independent slip systems, which is why FCC metals are the ductile, formable ones.
It is reported in 2 oxidation states (1, 2), which sets how many distinct compounds and phases it can form.
First identified in 1790.
Crystal structure
Solid Strontium adopts a Face-centered Cubic arrangement, in the Cubic (isometric) system — axes a = b = c, angles α = β = γ = 90°. Symmetry controls the anisotropy of stiffness and thermal expansion, and the available slip systems set how far the metal deforms before it fractures.
Check it against computed structures
The structure search queries the Materials Project, OQMD and the Open Materials Database for computed crystal structures containing Sr — with DFT formation energy, hull stability and band gap where the provider publishes them.
K 2 · L 8 · M 18 · N 8 · O 2
Properties
| Atomic number | 38 |
|---|---|
| Atomic mass | 87.621 u |
| Series | alkaline earth metal |
| Group | 2 |
| Period | 5 |
| Block | s-block |
| Phase at STP | Solid |
| Density | 2.63 g/cm³ |
| Melting point | 1050 K (777 °C) |
| Boiling point | 1650 K (1377 °C) |
| Electronegativity (Pauling) | 0.95 |
| Electron configuration | [Kr] 5s² |
| Crystal structure | Face-centered Cubic |
| Oxidation states | 1,2 |
| Discovered | 1790 |
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See Sr in context with all 118 elements.
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