Uranium

Element 92 on the periodic table, symbol U, group 3, period 7.

Uranium is a chemical element with symbol U and atomic number 92. It is a silvery-white metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons.

Properties

Atomic Number: 92
Atomic Mass: 238.0289 u
Group: 3
Period: 7
Block: f-block
Category: Actinide
State at 25 °C: Solid
Melting Point: 1,405.3 K · 1,132.2 °C
Boiling Point: 4,404 K · 4,130.9 °C
Density: 19.1 g/cm³
Atomic Radius: 175 pm
Electronegativity: 1.38
Oxidation States: +3, +4, +5, +6
Abundance in Crust: 2.7 mg/kg
Discovered: 1789
Discovered By: Martin Heinrich Klaproth

Electron Configuration

[Rn] 5f3 6d1 7s2

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f3 6d1

Ionisation Energies (kJ/mol)

1. 597.6
2. 1,420

Elements near Uranium

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.