For the symbol H, D and T tabulate three sub-atomic particles found in each of them.

plz explain me this question and tell the answer also

An atom is made up of three subatomic particles that are protons, neutrons and electrons. These (H, D and T) are isotopes of hydrogen atom.

Isotopes are defined as atoms having the same atomic number, but different mass numbers. These atoms contain an equal number of protons and electrons, but a different number of neutrons.

For example, in nature, hydrogen is found in three forms with different mass numbers, namely protium (), deuterium(), and tritium (). These are the three naturally occurring isotopes of hydrogen. The atomic number of each isotope is 1, but the mass number varies i.e. it is 1, 2, and 3 respectively.