16. Using number 15 as a guide, calculate the rate constant for the same reaction performed at A 256 *10^3 L/(mol. S)
B 3.18*10^1 L/(mol. S)
C. 7.62*10^-6 L/(mol. S)
D 3.15*10^-3 L/(mol. S)
E 3.14*10^-2 L/(mol. S)

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.

that tool would be a compass

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.