Divergent plate boundary is when two plates come together true or false

False, divergent boundaries are when two plates move away from each other.

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.

the answer is na (sodium)