Maria wants to determine which type of disinfectant kills the most bacteria. which of the following is the best way for maria to determine this? a. ask ten different companies that make disinfectants which type is best. b. put the same amount and species of bacteria on ten identical plates, and add ten different kinds of disinfectant to each plate. c. interview ten different people to determine which type of disinfectant they prefer. d. put the same amount and species of bacteria on ten identical plates, and add a different disinfectant to each plate.

D. Put the same amount and species of bacteria on ten identical plates, and add a different disinfectant to each plate.

Explanation:

Maria can perform experiment to determine which disinfectant is better for killing most of the bacteria. The type of disinfectant can become the independent variable and the bacteria can become the dependent variable. The independent variable changes manually so as to produce change on the dependent variable.

On keeping 10 different plates and placing different disinfectants and observing the growth of bacteria can give indication of which disinfecatant is the best. The plate with less population of bacteria will be the best disinfectant.

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.