Answer: Out of the given options bonds connecting atoms in reactants break, and bonds connecting atoms in products form are the changes which takes place when a chemical change occurs.
Explanation:
A change that leads to the change in chemical composition of a substance is called a chemical change.
For example, 
Here, bond between the reactant atoms nitrogen and hydrogen is broken down.
On the other hand, bond connecting the products that is 
and 
is formed.
Thus,, we can conclude that out of the given options bonds connecting atoms in reactants break, and bonds connecting atoms in products form are the changes which takes place when a chemical change occurs.
Answer: Out of the given options acetic acid is in household vinegar.
Explanation:
Household vinegar is the one that is commonly used in our home while cooking a number of dishes.
The common name of vinegar is acetic acid and its chemical formula is 
.
For example, vinegar (acetic acid) is used while making noodles.
Thus, we can conclude that out of the given options acetic acid is in household vinegar.
The melting of solid wax to form liquid wax and the evaporation of liquid wax to form wax vapor are physical changes. The burning of the wax vapor is a chemical change.
The specific gravity of water is 1.0 True
C. Rubbing the balloon against your hair
