Question

The number of neutrons in heavy hydrogen atom is:
A.$0$
B.$1$
C.$2$
D.$3$

Answer 1

Hint:We can calculate the number of neutrons by subtracting the mass number to number of protons. The sum of the protons and neutrons in the nucleus is known as mass number. The number of protons present in the nucleus is the atomic number.

Complete step by step answer:
The sum of the protons and neutrons in the nucleus is known as mass number.
The number of protons present in the nucleus is the atomic number.
For an element ${\text{E,}}$ the top left number represents the mass number and the bottom left number represents the atomic number.

Image drawn in chemdraw by SME.
The letter A represents mass number.
The letter Z represents atomic numbers.
Heavy hydrogen atom is Deuterium. It is one of the two stable isotopes of hydrogen.
The symbol of a heavy hydrogen atom is ${^2_1}H$.
We can give the number of protons as,
The number of protons in the nucleus is equal to the atomic number of an atom.
The atomic number of heavy hydrogen is $1$.
The number of protons in heavy hydrogen is $1$.
The mass number of a heavy hydrogen atom is $2$.
We can calculate the number of neutrons present in the heavy hydrogen by subtracting the mass number from the number of protons.
We know that the number of protons of heavy hydrogen is one and the mass number of heavy hydrogen is two.
We can write the formula to calculate the number of neutrons as,
Number of neutrons=${\text{Mass}}\,{\text{number - Number}}\,{\text{of}}\,{\text{protons}}$
Number of neutrons=${\text{2 - 1}}$
Number of neutrons=$1$
The number of neutrons present in a heavy hydrogen atom is $1$.
Therefore, option (B) is correct.


Note:
We can represent Deuterium using the symbol D. Protium in water molecules is replaced by Deuterium to form heavy water. We can use deuterium in heavy water moderated fission reactors, generally as liquid \[{D_2}O\] to slow neutrons without the high neutron absorption of ordinary hydrogen. We could use deuterium in NMR spectroscopy. We can use deuterium as a non-radioactive, stable isotopic tracer.