Statement 2 is correct.
solids moving into solution is a physical change as the core structure of the molecules remain the same. evaporation of water and crystallization of salt are both physical changes as well.
The water does not change it's H2O chemical makeup because salt was dissolved into it.
Did you mean the atomic mass?
I’m pretty sure it’s 7.5 (7 and a half hours) sorry if i’m wrong
