Compare Elements

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

Swap
Element comparison
Property Ac Actinium La Lanthanum
Atomic Number 89 higher 57 higher
Symbol Ac different La different
Name Actinium different Lanthanum different
Atomic Mass 227.0277 higher 138.9055 higher
Category Actinides different Lanthanides different
Period 7 higher 6 higher
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 same value 1.1 same value
Atomic Radius 260 higher 240 higher
Ionization Energy 5.17 lower 5.577 lower
Electron Affinity — no data 0.5 no data
Oxidation States +3 same value +3 same value
Melting Point 1324 K (1050.85 °C) higher 1191 K (917.85 °C) higher
Boiling Point 3471 K (3197.85 °C) lower 3737 K (3463.85 °C) lower
Density 10.07 higher 6.15 higher
Electron Configuration [Rn]7s2 6d1 different [Xe]6s2 5d1 different
Year Discovered 1899 different 1839 different

higher lower