Question

If an element has an atomic number of 15 then (a) the atomic mass must also be 15 (b) the atom has 15 electrons (c) there are 7 electrons in the outermost shell (d) the atom has 15 neutrons (e) the atom must have only one orbital

Answer 1

A

Step-by-step explanation:

It won't be B because the electron number goes on the upper right corner and there will only be a number there if it is different from the number of protons. Not C because all electrons are on the outer shell. An atomic number is the number of an element's neutrons plus protons. All elements only have one orbital so it can't be E, leaving the only possible answer as A.