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.
I think you forgot to give the options along with the question. I am answering the question based on my knowledge and research. "Test a third group that does not receive the supplement" would be the procedure that would have made the <span>outcome of this study more valid. I hope the answer helps you.</span>
Answer:
the sun
water and
grassland?
sorry but whats the 3rd photo?
Explanation: