
- Who
- Caesium
- What
- 0.2 total number
- Where
- Not Applicable ()
Caesium with a Mohs value of just 0.2, is soft enough to be cut with a butter knife. It melts at just 28°C (82°F) and explodes violently when dropped in water. Silvery-gold in colour, its most notable use is in super-accurate atomic clocks.