all the data in one app

Your periodic table, always with you.

Use it offline. Find elements quickly. Keep favorites and personal notes on iPhone and iPad.

Table

232.04

Th

Thorium

Identification

CAS Number: 7440-29-1

Discovery Year: 1828

Discoverer: Jöns Berzelius

Discovery Location: Sweden

Properties

Atomic Mass: 232.0377 →Density: 11.7 g/cm³ →

Crust Abundance: 9.6 mg/kg

Crystal Structure: FCC

Atomic Dimensions

Atomic Radius: 180 pm →

Atomic Radius (Rahm): 288 pm

Covalent Radius: 206 pm →

Van der Waals Radius: 245.00000000000003 pm

Atomic Volume: 19.8 cm³/mol

Lattice Constant: 5.08 Å

Thermodynamics

Melting Point: 2028 K →Boiling Point: 5060 K →Specific Heat: 0.113 J/(g·K) →Heat of Fusion: 16.11 kJ/mol →Heat of Vaporization: 513.7 kJ/mol →

Heat of Formation: 602 kJ/mol

Electronic Structure

Electron Config: [Rn] 6d2 7s2

Block: f

Period: 7 →Electronegativity: 1.3 →

Oxidation States: +4

Abundance & Geochemistry

Crust Abundance: 9.6 mg/kg

Sea Abundance: 0.000001 mg/L

Geochemical Class: rare earth & related

Goldschmidt Class: litophile

About

Grey radioactive metallic element. Belongs to actinoids. Found in monazite sand in Brazil, India and the US. Thorium-232 has a half-life of 1.39x10^10 years. Can be used as a nuclear fuel for breeder reactors. Thorium-232 captures slow Neutrons and breeds uranium-233. Discovered by Jons J. Berzelius in 1829.