How many moles of tungsten atoms are in 4.8 x 1025 atoms of tungsten?

The valence of aluminum is +3, and the valence of the chlorine is -1. the formula fir the aluminum chloride is correctly written as

Describe what happens to the molecules as water goes from ice to liquid to vapor. be sure to explain what happens to the temperature during the phase changes.

Which factor is likely to impact the possible number of compounds ?