Write the formula equation, the overall ionic equa- tion, and the net ionic equation for the neutralization
reaction involving aqueous solutions of H3PO4 and
Mg(OH)2. Assume that the solutions are sufficiently
dilute so that no precipitates form.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

idk what the question is about