Compare Elements

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

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Element comparison
Property Cs Cesium Hf Hafnium
Atomic Number 55 lower 72 lower
Symbol Cs different Hf different
Name Cesium different Hafnium different
Atomic Mass 132.9055 lower 178.49 lower
Category Alkali Metals different Transition Metals different
Period 6 same value 6 same value
Group 1 lower 4 lower
Block s-Block different d-Block different
Standard State Solid same value Solid same value
Electronegativity 0.79 lower 1.3 lower
Atomic Radius 343 higher 212 higher
Ionization Energy 3.894 lower 6.825 lower
Electron Affinity 0.472 no data — no data
Oxidation States +1 different +4 different
Melting Point 301.59 K (28.44 °C) lower 2506 K (2232.85 °C) lower
Boiling Point 944 K (670.85 °C) lower 4876 K (4602.85 °C) lower
Density 1.93 lower 13.3 lower
Electron Configuration [Xe]6s1 different [Xe]6s2 4f14 5d2 different
Year Discovered 1860 different 1923 different

higher lower