Which molecule or compound below contains a nonpolar covalent bond? which molecule or compound below contains a nonpolar covalent bond? zns ncl3 k i agf?

Option (b) is the correct answer.

Explanation:

A non-polar covalent bond is formed due to equal sharing of electrons between the combining atoms.

For example, is a non-polar covalent molecule.

Atomic number of nitrogen is 7 and its electronic distribution is 2, 5. So, a nitrogen atom needs three more electrons to attain stability. Hence, when it combines with three chlorine atoms then there occurs equal sharing of electrons.

Thus, we can conclude that compound has a non-polar covalent bond.

So are you asking how would the particle size of the zinc affect the rate of its dissolution?
you must now that the bigger the particle the lesser the dissolution.
The reaction rate will go as the total surface area, therefore, the smaller the particles the faster the reaction. 
This relationship is NOT linear.