Calcium is a chemical element with symbol Ca. It is an alkaline earth metal present in the second group of periodic table. The atomic number of calcium is 20 and its atomic mass is 40. So, the number of electrons and number of protons in an atom of calcium is 20. The number of neutrons is equal to the difference of atomic mass and atomic number.
Atomic number = number of protons = number of electrons = 20
Atomic mass = number of protons + number of neutrons
Number of neutrons = atomic mass - atomic number = 40 - 20
Number of neutrons = 20
Atomic number = number of protons = number of electrons = 20
Atomic mass = number of protons + number of neutrons
Number of neutrons = atomic mass - atomic number = 40 - 20
Number of neutrons = 20