one isotope of chromium (atomic number 24) has an atomic mass of 53 amu. how many neutrons are in this particular isotope of chromium?

Question

A. 24
B. 29
C. 53
D. 77

I say A

Answer 1

#protons + #neutrons = mass #.
I don't agree with A as the answer.

Answer 2

Look at the equation I gave you. # protons is the atomic number. That's 24. Mass # in the problem is 53.
# neutrons = 53-24 = ?

Answer 3

got it now B