What is the name of Fe(NO3)3

When a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false

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.

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.