Atoms of element X weigh 32 times more than atoms of element Y. A compound has the formula: XY2 The ratio of the mass of X to the mass of Y in this compound equals: g

16:1

Explanation:

Atoms of element X weigh 32 times more than atoms of element Y. We can write this in a symbolic way.

mX = 32 mY   [1]

where,

A compound has the formula: XY₂, that is, in 1 molecule of XY₂ there is 1 atom of X and 2 atoms of Y. The ratio of the mass of X to the mass of Y in this compound equals:

mX/2 mY  [2]

If we substitute [1] in [2], we get:

mX/2 mY = 32 mY/2 mY = 16 = 16:1

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.