What are supporting details to the main idea: energy is the ability to cause change in matter

What is the internal energy of 4.00 mol of diatomic nitrogen gas n2 at 455k

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.

Directions: count the number of atoms. ar co2 na3po4 so3 nac2h3o2