If an atom of tin(Sn) has a mass number of 118 and an atomic number of 50, how many neutrons are in its nucleus?
A.
168
B.
118
C.
50
D.
68
To find the number of neutrons in the nucleus of an atom, you subtract the atomic number from the mass number.
Neutrons = Mass Number - Atomic Number
Neutrons = 118 - 50
Neutrons = 68
Therefore, the correct answer is:
D. 68