Question

Fill in the blanks with suitable words:
The fundamental particle not present in a normal hydrogen atom is ________.

Answer 1

The atomic mass as well as the atomic number of hydrogen is 1 u. The atomic mass is the sum of the number of protons and neutrons present in the nucleus. The atomic number is the number of protons. Therefore the normal hydrogen doesn't consist of neutron.

The isotopes of hydrogen that deuterium and tritium consist of 1 and 2 neutrons respectively.