SymbolSr
Latin nameStrontium
Atomic number38
Period5
Element categoryAlkaline earth metals
Relative atomic mass87.62
GroupII.A
Electronegativity
1.0
Oxidation numbers
2
Electron configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s2
Density [g/cm3]
2.6
State
Solid
Melting point [°C]
769
Boiling point [°C]
1384
Atomic radius [pm]
219
Covalent radius [pm]
182
Thermal conductivity [W m-1K-1]
35.3
Heat capacity [J K-1g-1]
0.3
Discovery
1790
Hardness [Mohs scale]
1.8
Electrical conductivity [S m-1]
2 · 106
1.st ionization energy [eV]
5.6948
2.nd ionization energy [eV]
11.03
3.rd ionization energy [eV]
43.6
Stable isotopes
4
Unstable isotopes
13