Describe the atomic composition of isotopes se 79 at the top 34 at the bottom and h 200 at the top and 80 at the bottom.

The numbers of protons and electrons in an atom are equal to each other, denoted by the number below and coincide with the ordinal number of a chemical element in the periodic table. The number of neutrons in an atomic nucleus is equal to the mass of the nucleus (number above) minus the number of protons.

p (34Se79) = 34;

e (34Se79) = 34;

n (34Se79) = 79 – 34 = 45;

p (80Hg200) = 80;

e (80Hg200) = 80;

n (80Hg200) = 200 – 80 = 120.