What causes the phase of the Moon
to change?

As the moon orbits the Earth and rotates, light from the Sun strikes it in different areas, changing the extent to which it is visible on earth. This interplay between the earth, moon and light from the sun is what causes the phases of the moon.

conduction is the transfer of thermal energy (heat in transfer) due to collisions between the molecules in the object. collisions between adjacent atoms and molecules transfer kinetic energy from the warmer to the cooler object. the objects must be in physical contact.