A). 4
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That would be 1 becuase A is N while B has its own value, so if B is 2 and That equals C A would be 1
Answer:
Temperature is not a chemical change because when a substance changes in temperature, its chemical makeup is not changing.
Answer:

Explanation:
The solid consists of positive and negative ions, so it is an ionic solid.
Ionic solids are brittle, usually water-soluble, and poor thermal conductors as solids. Thus, the correct answer is
.
(A) is wrong. It describes a covalent solid, which is soft and always a poor conductor.
(B) is wrong. It describes a covalent solid, which is also low-melting.
(D) is wrong. It describes a metal, and a metal does not contain negative ions.
When a chemical reaction occurs, molecular bonds are broken and other bonds are formed to make different molecules.
For example, the bonds of two water molecules are broken to form hydrogen and oxygen. Energy is always required to break a bond. Hope this helps you!