Chemical Elements.com - Thorium (Th)

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Basic Information

Name: Thorium
Symbol: Th
Atomic Number: 90
Atomic Mass: 232.0381 amu
Melting Point: 1750.0 °C (2023.15 K, 3182.0 °F)
Boiling Point: 4790.0 °C (5063.15 K, 8654.0 °F)
Number of Protons/Electrons: 90
Number of Neutrons: 142
Classification: Rare Earth
Crystal Structure: Cubic
Density @ 293 K: 11.72 g/cm³
Color: silvery

Atomic Structure

Number of Energy Levels: 7

First Energy Level:

Second Energy Level:

Third Energy Level:

Fourth Energy Level:

Fifth Energy Level:

Sixth Energy Level:

Seventh Energy Level:

Isotopes

Isotope	Half Life
Th-226	30.6 minutes
Th-227	18.72 days
Th-228	1.91 years
Th-229	7340.0 years
Th-230	75400.0 years
Th-231	1.06 days
Th-232	1.4E10 years
Th-233	22.3 minutes
Th-234	24.1 days

Facts

Date of Discovery: 1828
Discoverer: Jons Berzelius
Name Origin: Thor (Scandinavian god)
Uses: strong alloys, ultraviolet photoelectric cells
Obtained From: monazite, thorite

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