Element 38
Strontium (Sr)
Strontium (Sr) is element 38 of the periodic table, a alkaline earth metal in period 5, group 2 (s-block) with an atomic mass of 87.62 and is a solid at standard conditions.
At a glance
- Atomic number
- 38
- Symbol
- Sr
- Atomic mass
- 87.62 u
- Category
- Alkaline earth metals
- Period
- 5
- Group
- 2
- Block
- s-block
- Phase at STP
- solid
Electron structure
- Electron configuration
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s2
- Shorthand configuration
- [Kr] 5s2
- Electrons per shell
- 2, 8, 18, 8, 2
- Oxidation states
- +1, +2
Physical properties
- Melting point
- 1050 K
- Boiling point
- 1655 K
- Density
- 2.64 g/cm3
- Phase
- solid
Atomic properties
- Electronegativity (Pauling)
- 0.95
- Atomic radius
- 219 pm
- Covalent radius
- 195 pm
- Van der Waals radius
- 249 pm
- First ionization energy
- 550 kJ/mol
- Electron affinity
- 5 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| Sr-88 | 87.90561 | 82.58% | Stable |
Common uses
- Fireworks
- Ferrite magnets
- Toothpaste
- Glow-in-dark paints
Discovery
- Year
- 1790
- Discovered by
- Adair Crawford
- Country
- Scotland