Classify the reactions as endothermic or exothermic.

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.

i think the answer is terrae but not 100 percent sure. ▓▬▬ §