This hydrocarbon is incomplete. Draw the hydrogen atoms and the bonds connecting them to carbon atoms such tha each carbon atom has four bonds. Then record the number of hydrogen atoms you drew using a text box.

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.

explanation: no but i do not usually comment

5.6⋅10−^19  j

do you need the explaination?