Impure samples have melting point ranges that are both blank 1. fill in the blank, read surrounding text. and blank 2. fill in the blank, read surrounding text. compared to a pure sample.

1 Lower

2 wider

Explanation:

It is lower and wider in range because impurities affects the crystalline lattice of sample structure theory causing a deviation from real melting point of pure sample.

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.