+2, because the element has more protons than electrons now
The gravitation field strength of Planet X is 10 times that of Earth's, as the object weight has increased 10 times. This is only possible if the planet is more massive or more dense (smaller diameter).
Therefore, the answer is C.
To determine the masses of each component, we need to know the concentration first in terms of molality which is mol per mass of solution. Assuming the density of the solution is equal to that of water we would find:
molality = 0.160 mol KBr / L ( 1 L / 1 kg solution ) = 0.160 mol KBr / kg solution
mass KBr = 0.160 mol KBr / kg solution (.0750 kg solution ) ( 119 g KBr / mol KBr ) = 1.428 g KBr
mass solvent = 75 - 1.428 = 73.572 g water