What is an example of a chemical change? a. water evaporating from a puddle b. cloth tearing when pulled c. wood forming sawdust when cut d. bread baking in an oven

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.