Compare Elements

Compare two chemical elements side by side across 19 atomic and physical properties.

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Element comparison
Property La Lanthanum Th Thorium
Atomic Number 57 lower 90 lower
Symbol La different Th different
Name Lanthanum different Thorium different
Atomic Mass 138.9055 lower 232.038 lower
Category Lanthanides different Actinides different
Period 6 lower 7 lower
Group 3 same value 3 same value
Block f-Block same value f-Block same value
Standard State Solid same value Solid same value
Electronegativity 1.1 lower 1.3 lower
Atomic Radius 240 higher 237 higher
Ionization Energy 5.577 lower 6.08 lower
Electron Affinity 0.5 no data — no data
Oxidation States +3 different +4 different
Melting Point 1191 K (917.85 °C) lower 2023 K (1749.85 °C) lower
Boiling Point 3737 K (3463.85 °C) lower 5061 K (4787.85 °C) lower
Density 6.15 lower 11.72 lower
Electron Configuration [Xe]6s2 5d1 different [Rn]7s2 6d2 different
Year Discovered 1839 different 1828 different

higher lower