← Periodic Table
90
f🧱
Th
232.0400

Thorium

Actinide

Atomic Properties

Atomic Number
90
Atomic Mass
232.0400 u
Electron Configuration
[Rn] 6d2 7s2
Electronegativity
1.30
Block
f-block
Group
Period
7

🌡 Physical Properties

Phase (STP)
solid
Melting Point
2023.00 K
Boiling Point
5061.00 K
Density
11.7000 g/cm³

About Thorium

Radioactive; potential nuclear fuel; more abundant than uranium.

🔬 Isotopes of Thorium

Thorium has 1 naturally occurring isotope, plus 1 notable radioactive isotope.

IsotopeMass NumberAtomic Mass (u)AbundanceType
230Th230230.0331341Radioactive
232Th232232.0380558100.00%Stable

Data source: NIH PubChem (aggregated from IUPAC, NIST)