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38Sr87.621
Strontium
Alkaline Earth MetalStrontium is a chemical element with symbol Sr and atomic number 38. An alkaline earth metal, strontium is a soft silver-white or yellowish metallic element that is highly reactive chemically. The metal turns yellow when it is exposed to air.
Phase: Solid
2, 8, 18, 8, 2
Physical Properties
Atomic Mass87.621 u
Density2.64 g/cm³
Melting Point1050 K
Boiling Point1650 K
Molar Heat26.4 J/(mol·K)
Period5
PhaseSolid
Chemical Properties
Electron Configuration1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2
Semantic Config[Kr] 5s2
Shells2, 8, 18, 8, 2
Electron Affinity5.023 kJ/mol
Electronegativity0.95
Ionization Energies
IE1: 549.5 kJ/molIE2: 1064.2 kJ/molIE3: 4138 kJ/molIE4: 5500 kJ/molIE5: 6910 kJ/molIE6: 8760 kJ/molIE7: 10230 kJ/molIE8: 11800 kJ/molIE9: 15600 kJ/molIE10: 17100 kJ/molIE11: 31270 kJ/mol
Discovery
Discovered byWilliam Cruickshank (chemist)