The energy diagram shown represents the chemical reaction between solid ammonium chloride and solid barium hydroxide octahydrate: 2NH4Cl(s+Ba(OH)2⋅8H2O(s)→NH3(aq)+Ba Cl2(aq)+10H2O(l)

The ΔH for this reaction is 54.8 kJ . How much energy would be absorbed if 24.9 g of NH4Cl reacts?

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 your looking for is c).