It would have 45 protons, as the atomic number is equivalent to the amount of protons
The molecules making up object collide with the molecules of the other and some of the kinetic energy from a warmer object is transferred to the cooler one.
Earth's atmosphere is a <em>mixture</em> of gases that have
not reacted to become chemical compounds.
I'm not sure about the magnitude, but the direction of the normal force is upward.
