Answer
Protons: 24
Neutrons: 27
Work Step by Step
The atomic number, as shown by the periodic table, of Chromium is 24, meaning that there are 24 protons (the atomic number is the number of protons). Because it is Chromium-51, the atomic mass number of this isotope is 51 amu. Because both protons and neutrons weigh one amu while electrons are essentially weightless, this means that there must be 27 neutrons (24 protons+27 neutrons= 51 amu).