Strontium

Koushik 26/06/2026 19:58:08 Updated 26/06/2026 19:58:08

Property	Value
Atomic Number	38
Element	Strontium
Symbol	Sr
Atomic Mass	87.62 u
Number of Neutrons	50 (most common isotope, Strontium-88)
Number of Protons	38
Number of Electrons	38
Period	5
Group	2
Phase	Solid
Radioactive	No (contains naturally occurring radioactive isotope Sr-90 in trace/artificial contexts)
Natural	Yes
Metal	Yes
Nonmetal	No
Metalloid	No
Type	Alkaline Earth Metal
Atomic Radius	219 pm
Electronegativity	0.95 (Pauling scale)
First Ionization Energy	5.695 eV
Density	2.64 g/cm³
Melting Point	777 °C
Boiling Point	1382 °C
Number of Isotopes	4 stable (Sr-84, Sr-86, Sr-87, Sr-88)
Discoverer	William Cruickshank
Year	1790
Specific Heat	0.301 J/g·K
Number of Shells	5
Number of Valence Electrons	2