Atomic number: 31

Symbol: Ga

Category: post-transition metal

Density at 25°C: solid:  5.91 g·cm−3

Gallium melts at quite a low temperature for a metal, around 29.77 °C so it can start to melt if held in the hand long enough.  But it is most used in electronics for microwaves and infrared. It has the largest liquid ranges for a metal.

A chunk of solid gallium crystal. image: adapted from wikipedia

Use, natural applications or common combinations: 

  • UV and blue LED lasers
  • Biomedical applications
  •  Gallium arsenide, is used in microwave circuits
  • Semi conductors
  • Temperature standard

Basic characteristics:

  • Standard atomic weight: 69.723(1)
  • Melting point: 29.7646 °C
  • Boiling point: 2204 °C
  • Radioactivity:  all stable naturally
    • 67Ga is used in medical scanning as a tracer. half-life 3.3 days emitting gamma rays.