Use your knowledge of atoms, bonding, and the periodic table to complete the chemical equation .”CH4 + O2 and predict the products of the chemical reaction on your paper. Label this equation “Initial Prediction.

CH4 + O2 = CO2 + H2O.

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.