To find the number of neutrons in an atom of a specific isotope, you can subtract the atomic number (which represents the number of protons) from the mass number (which represents the sum of protons and neutrons).
For chromium-52 (52Cr):
Atomic number (number of protons) = 24
Mass number (number of protons + number of neutrons) = 52
Number of neutrons = Mass number - Atomic number
Number of neutrons = 52 - 24 = 28
So, an atom of 52Cr has 28 neutrons.