Help!!

I'm not sure my answer is correct.

The problem is attached!

Which best represents the law of conservation of mass ?

Consider an insulating crystal, made up of layers of atoms. what form would you expect the temperature dependence of the phonon heat capacity to approach at extremely low temperatures if the interlayer coupling is i)very strong (rigid coupling), and ii) very weak. explain.

Write down two additional questions about earth's magnetic field that will make your presentation more informative.