Compare Elements

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

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Element comparison
Property Na Sodium K Potassium
Atomic Number 11 lower 19 lower
Symbol Na different K different
Name Sodium different Potassium different
Atomic Mass 22.9898 lower 39.0983 lower
Category Alkali Metals same value Alkali Metals same value
Period 3 lower 4 lower
Group 1 same value 1 same value
Block s-Block same value s-Block same value
Standard State Solid same value Solid same value
Electronegativity 0.93 higher 0.82 higher
Atomic Radius 227 lower 275 lower
Ionization Energy 5.139 higher 4.341 higher
Electron Affinity 0.548 higher 0.501 higher
Oxidation States +1 same value +1 same value
Melting Point 370.95 K (97.8 °C) higher 336.53 K (63.38 °C) higher
Boiling Point 1156 K (882.85 °C) higher 1032 K (758.85 °C) higher
Density 0.97 higher 0.89 higher
Electron Configuration [Ne]3s1 different [Ar]4s1 different
Year Discovered 1807 same value 1807 same value

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