Answer 1) What is nuclear fission and nuclear fusion?Â
Nuclear Fission - It is reaction process when a neutron is made to strike to an atom with a heavy nucleus. It makes the atom release certain number of neutrons from the nucleus, then it splits the parent atom into smaller other atoms.
Nuclear Fusion - It is exactly opposite of nuclear fission. It is a reaction process, where the nucleus of certain light atoms tries to join the nucleus of other lighter atoms together and release large amount of energy.
Answer 2) What happens in these reactions?
 Nuclear Fission - Usually in these reactions the atoms with heavy nucleus splits up into smaller atoms. Fission means breaking into smaller atoms.
Nuclear Fusion - In this reaction the atoms of several lighter nucleus combines together to form a larger nucleus by releasing a high amount of energy. Fusion means joining/mixing of small atoms to form large atom.
Answer 3) Types of atoms involved?
Nuclear Fission -Â Atoms with heavy nucleus like uranium which when bombarded with neutrons can get splitted into smaller atoms of xenon or strontium,etc.
Nuclear Fusion - Atoms including small lighter nucleus combines to form larger  ones. For example, inside the Sun, the small atoms of hydrogen combines to form helium atoms which imparts sun a large amount of heat and light energy.
Answer 4) Types of product produced?
Nuclear Fission - Depending upon the atoms of heavy nucleus undergoing fission the products would be produced. Such as if uranium undergoes fission the products obtained will be different than Plutonium undergoing fission. Although several small by products may be similar.
Nuclear Fusion - This reaction also depending upon the smaller atoms nucleus which undergoes the process of fusion and result into a bigger atom. Example is the fusion of hydrogen atoms in sun and stars.
Answer 5) Practical Uses.
Nuclear Fission - As in this process large amount of energy is released, the major use is done in producing power. Also it's uses are seen in manufacturing of nuclear weapons.
Nuclear Fusion - It is difficult to do fusion reactions, but still we have managed to manufacture hydrogen bombs using this reaction and many researches are going on in the field of magnetism and laser beams.
Answer 6) Limitations.
Nuclear Fission -Â The major limitation in using this kind of reaction is because of the generation of radioactive wastes. It is difficult to dispose off the waste generated after the reaction with proper care. It effect remains years after years and are extremely toxic to all living beings.
Nuclear Fusion - It is quite difficult to nuclear fusion reaction on earth as it requires high amount of temperature and pressure. So it is almost impossible to replicate fusion reactions.
