Compare Elements

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

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Element comparison
Property Ar Argon Kr Krypton
Atomic Number 18 lower 36 lower
Symbol Ar different Kr different
Name Argon different Krypton different
Atomic Mass 39.9 lower 83.8 lower
Category Noble Gases same value Noble Gases same value
Period 3 lower 4 lower
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 — no data 3 no data
Atomic Radius 188 lower 202 lower
Ionization Energy 15.76 higher 14 higher
Electron Affinity — no data — no data
Oxidation States 0 same value 0 same value
Melting Point 83.8 K (-189.35 °C) lower 115.79 K (-157.36 °C) lower
Boiling Point 87.3 K (-185.85 °C) lower 119.93 K (-153.22 °C) lower
Density 0.0018 lower 0.0037 lower
Electron Configuration [Ne]3s2 3p6 different [Ar]4s2 3d10 4p6 different
Year Discovered 1894 different 1898 different

higher lower