Atoms of element X have 12 times the mass of atoms of oxygen, and atoms of oxygen have 16 times the mass of atoms of hydrogen. What is the mass of atoms of element X on a scale on which atoms of hydrogen have a mass of 1? A. 16/12
B. 12/16
С. 12 x 16
D. 16-12
E. 1216

C. 12 × 16

Explanation:

Let mH be the mass of atoms of hydrogen and mO be the mass of atoms of oxygen.  The atoms of oxygen have 16 times the mass of atoms of hydrogen. That is,

mO = 16 mH   [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   [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