An element's atomic number is 39. how many electrons would an atom of this element have?

What would be an example of hypothesis for goldfish respiration lab

Which of the following occurs most often in a population when genetic variation and overproduction are present? some organisms have a lower reproductive success than others. some organisms have a higher reproductive success than others. some organisms have no reproductive success. some organisms do not have genetic variation.

What is the importantence of the carbon and nitretan cycles in the environment