Indium

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

Property	Value
Atomic Number	49
Element	Indium
Symbol	In
Atomic Mass	114.818 u
Number of Neutrons	66 (most common isotope, Indium-115)
Number of Protons	49
Number of Electrons	49
Period	5
Group	13
Phase	Solid
Radioactive	No (contains naturally occurring radioactive isotope In-115)
Natural	Yes
Metal	Yes
Nonmetal	No
Metalloid	No
Type	Post-transition Metal
Atomic Radius	156 pm
Electronegativity	1.78 (Pauling scale)
First Ionization Energy	5.786 eV
Density	7.31 g/cm³
Melting Point	156.60 °C
Boiling Point	2072 °C
Number of Isotopes	2 naturally occurring (In-113, In-115)
Discoverer	Ferdinand Reich, Hieronymus Theodor Richter
Year	1863
Specific Heat	0.233 J/g·K
Number of Shells	5
Number of Valence Electrons	3