Curium

Element 96 on the periodic table, symbol Cm, group 3, period 7.

Curium is a transuranic radioactive chemical element with symbol Cm and atomic number 96. This element of the actinide series was named after Marie and Pierre Curie – both were known for their research on radioactivity. Curium was first intentionally produced and identified in July 1944 by the group of Glenn T. Seaborg at the University of California, Berkeley.

Appearance: silvery metallic, glows purple in the dark

Properties

Atomic Number: 96
Atomic Mass: 247.0000 u
Group: 3
Period: 7
Block: f-block
Category: Actinide
State at 25 °C: Solid
Melting Point: 1,613 K · 1,339.9 °C
Boiling Point: 3,383 K · 3,109.9 °C
Density: 13.51 g/cm³
Atomic Radius: 176 pm
Electronegativity: 1.28
Oxidation States: +3
Abundance in Crust: Vanishingly rare
Discovered: 1944
Discovered By: Glenn T. Seaborg

Electron Configuration

[Rn] 5f7 6d1 7s2

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f7 6d1

Ionisation Energies (kJ/mol)

1. 581

Elements near Curium

Elements in the same group share the number of outer electrons and behave in similar ways. Elements in the same period share a shell, so they change steadily from left to right.