How do particles of a gas differ from particles of a liquid when in the same container

Which statement is best described as a atom

Asolid that forms and separates from a liquid mixture is called

4.25g sample of solid ammonium nitrate dissolves in 60.0g of water in a coffee-cup calorimeter, the temperature drops from 22.0 c to 16.9 c. assume that the specific heat of the solution is the same as that of pure water. calculate delta(h) (in kj/mol nh4no3) for the solution proces.