Question

The number of neutrons present in deuterium isotope of hydrogen is
A. \[2\]
B. \[3\]
C. \[5\]
D. \[1\]

Answer 1

Hint: Here deuterium is \[_1^2H\] that is, atomic mass is \[2\] and atomic number is \[1\]. Atomic mass is a summation of number of protons and number of neutrons whereas atomic number is the number of protons in the nucleus.

Complete answer:
The mass number is written as a superscript and atomic number is written as a subscript on the element.
We know that, Deuterium isotope is \[1\]e is \[_1^2H\]
Here atomic mass of hydrogen = \[2\]
Atomic number of hydrogen = \[1\]
As we know number of neutrons = atomic mass – atomic number (number of protons)
Substituting above described atomic mass and atomic number in the above equation concept .
That is number of neutrons = \[2 - 1 = 1\]
Therefore 1 neutron is present in deuterium isotope
Hence, option D is the correct answer.

Additional information: Water molecules having deuterium content instead of normal hydrogen is known as Heavy hydrogen.
 Deuterium is prepared purely by electrolytic method.
 Deuterium is a stable isotope of hydrogen.
A wide and important application of deuterium is that it is alternately used in nuclear moderator as it is considered as the heavy water.
Actually deuterium behaves somewhat similar to ordinary hydrogen.
The most common application of deuterium is wide usage in NMR spectroscopy.
Deuterium occurs in trace amounts as deuterium oxide.
Nucleus of deuterium is termed as deuteron.
Hydrogen has three isotopes, protium, deuterium , tritium. They all differ only in the number of neutrons, and have the same number of protons and electrons. They are electrically neutral but they keep getting heavier in size as the number of neutrons increases.

Note:Always remember that the number of neutrons can be only calculated by knowing its actual mass number and atomic number from its isotope as we subtract atomic number from atomic mass. Isotopes of hydrogen have one electron to balance the charge of the one proton.