Britannica
Sources used in this answer
How do melting points change from lithium to cesium?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
alkali metal
Modern version of the periodic table of the elements (printable).
The melting points of the alkali metals decrease as you move down the group from lithium to cesium. Specifically, the melting points range from 180.5 °C for lithium to 28.44 °C for cesium.1
This downward trend occurs because the atomic size of these elements increases as you move down the periodic table, leading to larger interatomic distances in their crystal structures. These larger distances result in weaker bond energies, which directly causes the melting points to be lower for the heavier elements in the group.1