I can guess that Z is Phosphorus. So the oxide - P4O10 (but the most known its empirical formula P2O<span>5)</span>. Reaction with water:
P4O10 + 6H2O = 4H3PO4. Acidic compound is phosphoric acid.
Answer:
D. The number of it's protons
Dioxide gas because ita cooler
C because the more amounts of mass an object has will give it a bigger gravitational field
I think it’s B not quite sure ! Sorry