Compare Elements

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

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Element comparison
Property Pm Promethium Nd Neodymium
Atomic Number 61 higher 60 higher
Symbol Pm different Nd different
Name Promethium different Neodymium different
Atomic Mass 144.9128 higher 144.24 higher
Category Lanthanides same value Lanthanides same value
Period 6 same value 6 same value
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 — no data 1.14 no data
Atomic Radius 236 higher 229 higher
Ionization Energy 5.55 higher 5.525 higher
Electron Affinity — no data — no data
Oxidation States +3 same value +3 same value
Melting Point 1315 K (1041.85 °C) higher 1294 K (1020.85 °C) higher
Boiling Point 3273 K (2999.85 °C) lower 3347 K (3073.85 °C) lower
Density 7.26 higher 7.01 higher
Electron Configuration [Xe]6s2 4f5 different [Xe]6s2 4f4 different
Year Discovered 1945 different 1885 different

higher lower