Q. 1. For the symbol and
tabulate three sub-atomic particles found in each of them.
H, D, and T are the three isotopes of hydrogen with the same atomic number and different mass numbers of 1, 2 and 3 respectively.
| Element | Symbol | Number of Electrons | Number of Protons | Number of Neutrons |
| Hydrogen | H | 1 | 1 | 0 |
| Deuterium | D | 1 | 1 | 1 |
| Tritium | T | 1 | 1 | 2 |