Question

The total number of neutrons in all isotopes of hydrogen is equal to:

• A. 6
• B. 2
• C. 4
• D. 3

Answer 1

Answer: (D)

3

Hydrogen has 3 isotopes.

${}_1^1\text{H}$	${}_1^2\text{H}$	${}_1^3\text{H}$
neutron 0	1	2
proton 1	1	1

The total number of neutrons in all the isotopes of Hydrogen $=0+1+2=3$.