Answer:
1. True
2. true
3. True
4. False
Explanation:
1. In nuclear reaction, the nuclie are transformed to produce a large amount of energy. In fission reaction, one large nucleus breaks to form two small nucleus and produce energy. In fusion reaction,two nucleus combine to form a single large nucleus.
2. Uranium 235 used in nuclear reaction absorbs neutrons and form two smaller nucleus to produce large amount of energy.
Plutonium-239 also absorb neutrons and also fission with uranium-235 in a reactor.
3. Fusion reaction is uncontrollable. It occurs in the sun. It is a chain reaction which produce more and more energy along with neutrons. So it is uncontrollable.
Whereas , Fission reaction is controllable by using controlled rods.
4. Fusion reaction occurs at the sun to produce high temperature and energy and the sun glows.