Several scientists are working together to study the change in the number of whales born each year along the northern coast of california. what is the controlled parameter

I believe that in this case the controlled parameter is the type of animal that they are observing. There are a lot of animals in the ocean, therefore to have a scope of their study of observation, they are controlling or limiting their observations on the whale alone. Hence the controlled parameter is the type of animals, whales.

the atomic number will stay the same no matter how many electrons it has, so it doesn’t decrease nor increase. it’ll only change with a different number of protons