Ir

IRIDIUM

Definition from 'iris' or rainbow. it hardens metals for use of standard measures.

Discovery 1804 by smithson tennant of britain

Uses hypodermic needle, hardning agent

Group of Elements Late transition metals(SOlid)

Atomic Weight 192.217

Oxidation State +3,4

Melting Point 1966

Boiling Point 3727

Density 12.44 g/cm3

Electronegativity 2.2