
Answer:
C. 12 × 16
Explanation:
Let mH be the mass of atoms of hydrogen and mO be the mass of atoms of oxygen. Â The atoms of oxygen have 16 times the mass of atoms of hydrogen. That is,
mO = 16 mH Â [1]
Let mX be the mass of the atoms of X. Atoms of element X have 12 times the mass of atoms of oxygen. That is,
mX = 12 mO Â [2]
If we substitute [1] in [2], we get
mX = 12 × 16 mH
If mH is 1, we get,
mX = 12 × 16 × 1
mX = 12 × 16