Can someone answer these please i'll give 25 points it would mean alot to me <3

An electrons position cannot be known precisely only it's probability of being in a certain location can be known

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.

Which characteristics can be used to differentiate star systems? check all that apply.