Indicate the number of protons, neutrons, and electrons that exist, respectively, in the mercury atom The atomic number (Z) is the number of proto...

Indicate the number of protons, neutrons, and electrons that exist, respectively, in the mercury atom

The atomic number (Z) is the number of protons. This information appears in the lower left corner of the element symbol, that is, 53.
Since the mass number (A) is on the upper left side of the element symbol, that is, equal to 127, and this mass number is equal to the sum of protons and neutrons, we can find the number of neutrons as follows: A = p + n; n = A - p; n = 127 - 53; n = 74.
When the element is in the ground state, the number of electrons is exactly equal to the number of protons, being, therefore, equal to 53.
53, 127, 74
127, 53, 127
74, 127, 180
53, 74, 53
127, 74, 123