If an atom of an element has 11 protons and 12 neutrons in its nucleus, the mass number of the element is:

If an atom of an element has 11 protons and 12 neutrons in its nucleus

1.	If an atom of an element has 11 protons and 12 neutrons in its nucleus, the mass number of the element is:
A.	35
B.	12
C.	23
D.	11
Answer» D. 11