Select all properties that you included in your hypothesis. . . . High melting and boiling points and therefore solid at room temperature . . . A crystalline structure . . . Ability to dissolve easily in water . . . Ability to conduct electricity well

High melting and boiling points and therefore solid at room temperature

A crystalline structure

Ability to dissolve easily in water

Ability to conduct electricity well

Explanation:

The hypothesis mentioned in the question will be something like this

'If a substance is solid at room temperature, has a crystalline structure, dissolves easily in water, and conducts electricity well, then it likely contains ionic bonds. Otherwise, it likely contains covalent bonds'

We can see that all the items selected in the answer box were included in the hypothesis.

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.

i'm assuming that the correct answer is indeed the first one/ "a"..