BIOLOGY question #3 please?

Question

which of the following facts allows you to determine that atom A and atom B are isotopes of the same element?

a)they each have six protons

b)they each have four neutrons

c)in each, the sum of their electrons and neutrons is 14

d)they each have four valence electrons

e)they each have a mass number of 14

could you please tell me how you got this? thank you

my dad won't help me and i skipped a grade so i have no one to ask for help in class.

Answer 1

A.

The definition of an isotope is that the two different isotopes, of the same element, have the same amount of protons and electrons but different numbers of neutrons. The number of protons basically defines what element it is.

Answer 2

(a) they each have six protons.

Seriously, don't you have a textbook for your class you can look at?