1) This is a definition.
2) Protons are given by the bottom number (since atomic number = number of protons).
3) Neutrons = (mass number)-(atomic number), which are the top and bottom numbers, respectively.
4) Nuclear fusion involves combining two things together, which is only reflected by the last option.
5) This is a fact.
6) This is a fact.
7) This is a fact.
8) This is a fact.
9) The correct option is the explanation.
The amount or disorder in a chemical system or system is measured by it's Entropy. Entropy is the simply the measure of the amount of disorder or lack of structure present within a system.
Answer : The net ionic equation will be,

Explanation :
In the net ionic equations, we are not include the spectator ions in the equations.
Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.
The balanced ionic equation between zinc and hydrochloric acid will be,

The ionic equation in separated aqueous solution will be,

In this equation,
is the spectator ion.
By removing the spectator ion from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,

Explanation:
Here's what I came up with :)