Symbol Eu. A soft silvery metallic element belonging to the lanthanoids; a.n.63 r.a.m 151.96; r.d 5.245 (20°C); m.p 822 °C; b.p 1597 °C. It was discovered by Sir William Crookes in 1889.

It occurs in small quantities in bastanite and monazite. Two stable isotopes occur naturally europium-151 & europium-153 both of which are neutron absorbers.

Europium alloys have been tried for nuclear-reactor parts but until recently the metal has not been available in sufficient quantities. It is used in the form of the oxide in phosphorus for television screens.