Can some one help me in this question: Explain how air particles and air pressure are related.

Does the energy in a solid increase or decrease when changing to a liquid?

Write a net ionic equation to show that hydrofluoric acid, behaves as an acid in water.

In a heat of an engine, if 700 j enters the system, and the piston does 400 j of work what is the final internal (thermal) energy of the system if the initial energy is 1,500 j