Compare Elements

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

Swap
Element comparison
Property Rb Rubidium Fr Francium
Atomic Number 37 lower 87 lower
Symbol Rb different Fr different
Name Rubidium different Francium different
Atomic Mass 85.468 lower 223.0197 lower
Category Alkali Metals same value Alkali Metals same value
Period 5 lower 7 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 0.82 higher 0.7 higher
Atomic Radius 303 lower 348 lower
Ionization Energy 4.177 higher 3.9 higher
Electron Affinity 0.468 lower 0.47 lower
Oxidation States +1 same value +1 same value
Melting Point 312.46 K (39.31 °C) higher 300 K (26.85 °C) higher
Boiling Point 961 K (687.85 °C) no data — no data
Density 1.53 no data — no data
Electron Configuration [Kr]5s1 different [Rn]7s1 different
Year Discovered 1861 different 1939 different

higher lower