Question

For the symbol H, D and T, write the
subatomic particles (protons, neutrons and
electrons) found in each one of them.​

Answer 1

H stands for Hydrogen or protium.It has only one proton and one electron but no neutron.

D stands for duetrium. It has one proton, one electron and one neutron.

T stands for tritium. It has one proton, one electron and two neutrons.

Here, in all these three you can observe that the no. of protons and electrons i.e the atomic number is same but the atomic mass or mass number is different.Therefore, all three are isotopes of hydrogen element.