Question

The sun is considered as an ultimate source of energy. Justify this statement. What is thermonuclear fusion reaction? Write with chemical equation.​

Answer 1

Answer:

NUCLEAR FUSION

Fusion reactions in stars

Fusion reactions are the primary energy source of stars and the mechanism for the nucleosynthesis of the light elements. In the late 1930s Hans Bethe first recognized that the fusion of hydrogen nuclei to form deuterium is exoergic (i.e., there is a net release of energy) and, together with subsequent nuclear reactions, leads to the synthesis of helium. The formation of helium is the main source of energy emitted by normal stars, such as the Sun, where the burning-core plasma has a temperature of less than 15,000,000 K. However, because the gas from which a star is formed often contains some heavier elements, notably carbon (C) and nitrogen (N), it is important to include nuclear reactions between protons and these nuclei. The reaction chain between protons that ultimately leads to helium is the proton-proton cycle. When protons also induce the burning of carbon and nitrogen, the CN cycle must be considered; and, when oxygen (O) is included, still another alternative scheme, the CNO bi-cycle, must be accounted for. (See carbon cycle.)

Answer 2

• Plants convert light energy from the sun into chemical energy (food) by the process of photosynthesis. Animals eat plants and use that same chemical energy for all their activities. Hence, it is said to be an ultimate source of energy as it does many works.

• Thermonuclear fusion reaction is the process of atoms combining or “fusing” together with huge amounts of heat.

• Chemical equation :

H + H → D + β + + ν,

where β + represents a positron and ν stands for a neutrino. Before the reaction there are two hydrogen nuclei (that is, two protons).

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