Indium

Symbol: In
Atomic number: 49
Category: poor metals
Group: 13
Period: 5
Block: p
Atomic weight: 114.818 g/mol
Electrons per shell: 2, 8, 18, 18, 3
CAS number: 7440-74-6
Phase: solid
Density: 7.31 kg/dm³ (near room temperature)
Melting point: 429.7485 K (156.5985 °C, 313.8773 °F)
Boiling point: 2345 K (2072 °C, 3762 °F)
Crystal structure: tetragonal
Oxidation states: 3
Electronegativity: 1.78 (Pauling scale)
Name's origin: indicum
Name's meaning: a Latin word meaning indigo blue: spectral stripes of indium are bright blue
Facts:
- its primary application is to form transparent electrodes from indium tin oxide in liquid crystal displays
- is also used for making particularly low melting point alloys, and is a component in some lead-free solders
- radioactive indium-111 is used in nuclear medicine as an imaging agent to follow the movement of leukocytes in the body
- pure indium in metal form is considered non-toxic by most sources
- the first large-scale application for indium was as a coating for bearings in high-performance aircraft engines during World War II