Calcium

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

Property	Value
Atomic Number	20
Element	Calcium
Symbol	Ca
Atomic Mass	40.078 u
Number of Neutrons	20 (most common isotope, Calcium-40)
Number of Protons	20
Number of Electrons	20
Period	4
Group	2
Phase	Solid
Radioactive	No
Natural	Yes
Metal	Yes
Nonmetal	No
Metalloid	No
Type	Alkaline Earth Metal
Atomic Radius	194 pm
Electronegativity	1.00 (Pauling scale)
First Ionization Energy	6.113 eV
Density	1.55 g/cm³
Melting Point	842 °C
Boiling Point	1484 °C
Number of Isotopes	6 naturally occurring (Calcium-40, Ca-42, Ca-43, Ca-44, Ca-46, Ca-48)
Discoverer	Humphry Davy
Year	1808
Specific Heat	0.647 J/g·K
Number of Shells	4
Number of Valence Electrons	2