Answer:
true
Step-by-step explanation:
An atomic nucleus consists of protons and neutrons bound together. The mass of any nucleus other than Hydrogen is not the same as the sum of the masses of the individual protons and neutrons.
When two lighter nuclei are fused to a make heavier nucleus, the resulting nucleus is less massive than the sum of the the two original nuclei. The mass difference is converted into energy which is why fusion reaction release energy.