Question

The example of nuclear fusion is:
1.)Formation of barium and krypton from uranium
2.)Formation of helium from hydrogen
3.)Formation of plutonium-235 from uranium-235
4.)Formation of water from hydrogen and oxygen

Answer 1

Hint: Define what is a fusion reaction. In fusion reaction two or more light nuclei fuse to form a heavier nucleus. Compare the given reaction to this condition for fusion reaction. Then we can find our answer.

Complete step by step answer:
Nuclear fusion can be defined as a reaction where two or more lighter atomic nuclei combine to form one or more different atomic nuclei and other subatomic particles like neutrons and protons. there may be a difference in energy of the reactants and products which can be defined as the release or absorption of energy during the fusion process.

(i)The uranium nucleus absorbs a neutron and splits into a barium nucleus and a krypton nucleus. This is the fission reaction of a uranium nucleus.

(ii)In the formation of helium from hydrogen, four hydrogen nuclei fuse together to form a helium nucleus. This is a fusion reaction.

(iii)Formation of plutonium-235 from uranium-235 is not a fusion process. For a fusion process we need two or more lighter nuclei to fuse to form a heavier nucleus.

(iv)The formation of water from hydrogen and oxygen is an oxidation reaction or we can call it a redox reaction.

So, the fusion reaction will be the formation of helium from hydrogen.

The correct option is (B).

Note: In fusion reaction two or more nuclei fuse to produce one or more heavier nuclei. In fission reaction one heavier nuclei splits to form more that one lighter nuclei. The stars get their energy from fusion reactions only.