Question

What type of reaction occurring inside the sun produces the solar energy?
A. Nuclear fission reaction
B. Nuclear fusion reaction
C. Nucleophilic substitution reaction
D. Electrophilic addition reaction

Answer 1

Hint: Solar energy is the energy we get from the sun. Sun is a star, producing solar energy continuously from billions of years and will continue to do so for upcoming millions of years. Hence there must be an enormous amount of energy present within the sun or there must be a reaction going on. Only nuclear reactions can produce this much amount of energy.

Complete answer:
We will see all the reactions appearing in the respective options.

A. Nuclear fission reaction: It is a reaction which involves the splitting up of a heavy radioactive element into smaller elements, thereby releasing enormous amounts of energy. For example, uranium on bombardment with a neutron splits into krypton and barium along with some by-products and an enormous amount of energy. This energy can be produced in nuclear reactor labs to fulfill the requirements of electrical energy.

$U\quad +\quad n\quad \to \quad Kr\quad +\quad Ba\quad +\quad (Energy)$

B. Nuclear fusion reaction: It is a reaction which involves the combining or joining up of two smaller elements to convert into a heavier element, thereby releasing a huge amount of energy. This reaction requires very high temperature and pressure conditions, which can’t be achieved on earth. For example, two hydrogen isotopes combine to give a heavier element of Helium and release a huge amount of energy.

$H\quad +\quad H\quad \to \quad He\quad +\quad (Energy)$

C, D. Nucleophilic substitution reaction and electrophilic addition reactions: These are chemical reactions which are responsible for the formation of organic compounds with very less amount of energy released in the form of heat.

So, the correct answer is “Option B”.

Note:
For such types of questions, we need to see what reaction will produce maximum energy. The nuclear fission can be achieved on earth. Hence it has comparatively less energy associated with it. Also, it needs uranium in a huge quantity for ignition of the sun. Hence, in the sun, the pressure and temperature conditions are favorable for nuclear fusion.