Particles that are close together and locked in a place means its
a solid
1mol=6.022x10^23 atoms
3.75mol= 6.022x3.75x10^23 atoms
=2.2583x10^24 atoms
Reaction of Elemental Calcium with Water is as follow,
Ca + 2 H₂O → Ca(OH)₂ + H₂↑
When Sodium Metal is reacted with Water it produces NaOH and eliminates Hydrogen gas as shown in following equation,
2 Na + 2 H₂O → 2 NaOH + H₂↑
In both cases corresponding Hydroxides along with Hydrogen gas is produced.