Compare Elements

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

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Element comparison
Property Kr Krypton He Helium
Atomic Number 36 higher 2 higher
Symbol Kr different He different
Name Krypton different Helium different
Atomic Mass 83.8 higher 4.0026 higher
Category Noble Gases same value Noble Gases same value
Period 4 higher 1 higher
Group 18 same value 18 same value
Block p-Block same value p-Block same value
Standard State Gas same value Gas same value
Electronegativity 3 no data — no data
Atomic Radius 202 higher 140 higher
Ionization Energy 14 lower 24.587 lower
Electron Affinity — no data — no data
Oxidation States 0 same value 0 same value
Melting Point 115.79 K (-157.36 °C) higher 0.95 K (-272.2 °C) higher
Boiling Point 119.93 K (-153.22 °C) higher 4.22 K (-268.93 °C) higher
Density 0.0037 higher 0.0002 higher
Electron Configuration [Ar]4s2 3d10 4p6 different 1s2 different
Year Discovered 1898 different 1868 different

higher lower