If you clear volume in the density equation:

The greater the density the lower the volume. This means, the volume of gold nugget will be smaller than the volume of iron pyrite nugget.

Answer:
The correct answer is B) electronegativities of the bonded atoms in a molecule of the compound .
Explanation:
When two atoms forming a bond differ in their electronegativities at that time bond polarity is generated
In simple words a bond will be polar when the bonding electrons are not equally shared by two atoms.As a result the atom attract the bonding electron pair towards itself gain partial negative charge and the other atom gains partial positive charge.
For HCl is a polar compound because H and Cl atom differ in their electronegativities,as a result the bonding electron pair is not shared equally by H and Cl atoms.
I think the answer that you are looking for is B but im not a 100% sure
___AlBr3 + ___K -> ___KBr + ___ Al
1 AlBr3 + 3K -> 3KBr + 1 Al
hope this helps............