Strontium (Sr)
Alkaline earth metal · s-block · period 5 · group 2
Soft, silvery metal that quickly turns yellowish in air.
Strontium (symbol Sr) is chemical element number 38, a alkaline earth metal in group 2, period 5 of the periodic table. Its standard atomic weight is 87.62 and its electron configuration is [Kr] 5s2. At room temperature it is a solid. Named after Strontian, a village in Scotland where its ore was found.
Properties
| Atomic number | 38 |
|---|---|
| Atomic mass | 87.62 |
| Category | Alkaline earth metal |
| Block | s-block |
| Group · Period | 2 · 5 |
| Electron configuration | [Kr] 5s2 |
| Electrons per shell | 2, 8, 18, 8, 2 |
| State at 25 °C | solid |
| Melting point | 1050 K |
| Boiling point | 1650 K |
| Density | 2.64 g/cm³ |
| Electronegativity (Pauling) | 0.95 |
| Radioactive | No |
| Origin | primordial |
| Discovered | 1790 · Adair Crawford |
Key facts about Strontium
- Named after Strontian, a village in Scotland where its ore was found.
- Gives fireworks and warning flares their brilliant crimson-red colour.
- The body treats strontium like calcium and deposits it in bone.
- Radioactive strontium-90 from nuclear fallout is dangerous for exactly that reason.
What Strontium is used for
Red fireworks and flares, ferrite magnets, glow-in-the-dark paints, some medical treatments.
Where it sits in the periodic table
Strontium is in group 2, period 5, of the s-block. Its electron configuration [Kr] 5s2 means its outermost shell holds 2 electrons, which is what places it here and explains much of its chemistry. See Strontium on the interactive table →
Strontium — frequently asked questions
What is Strontium used for?
Red fireworks and flares, ferrite magnets, glow-in-the-dark paints, some medical treatments.
Is Strontium radioactive?
No. Strontium has at least one stable isotope and is not radioactive.
What is the electron configuration of Strontium?
Strontium has the electron configuration [Kr] 5s2, which is 2, 8, 18, 8, 2 electrons per shell.
What group and period is Strontium in?
Strontium is in group 2, period 5, in the s-block. Its outer shell holds 2 electrons.
Who discovered Strontium?
Strontium was discovered in 1790 by Adair Crawford.