Complete the equation
caco3+ ↠

Explanation:

CaCO3(s) + 2 HCl(aq) --> CaCl2(aq) + CO2(g) + H2O(l)

CaCl2 + CO2 + H2O

Explanation:

CaCO3 + 2HCl -> CaCl2 + CO2 + H2O There is one Calcium atom on the left and one Calcium atom on the right so this is balanced. There is 1 Carbon atom on the left and 1 Carbon atom on the right so this is balanced. There are 3 Oxygen atoms on the left and 3 Oxygen atoms on the right so this is balanced.

what are the two models

explanation:

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.