Compare how entropy changes for the following two systems: System A: A gas and a solid react to form a new solid product.

System B: Rubbing alcohol evaporates on the skin.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.