Which formula represents a solution?

No explanation needed.

Options:

NaOH (aq)

Explanation:

Defining state terminologies, 'aq' means aqueous, meaning the analyte is in solution, as opposed to gaseous (g), or liquid (l).

away from the curb

explanation:

the wheels would then hit the curb if it started to rolling, decreasing the chance of an accident.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.