What Is Nuclear Fusion?

Nuclear fusion is a form of nuclear energy. It's when two or more atoms' nuclei come together and form a new and heavier nucleus. During a nuclear fusion reaction energy is either released or absorbed. The release/absorbtion of energy all depends on the masses of the nuclei involved in the reaction. Elements with nuclei lighter than iron or nickel usually release engery, while elements that are heavier generally absorb engery. Nuclear fusion is basically the exact opposite of nuclear fission. But unlike fission, the amount of fusion that can occur has no limit. The different types of nuclear fusion reactions are cold fusion and hot fusion. Cold fusion is when fusion occurs at normal temperatures and the pressure is relatively low. Hot fusion creates high temperature and high pressure. Although the concept of nuclear fusion is simple, under controlled conditons it is difficult to achieve.

Examples of Nuclear Fusion:

Nuclear fusion is the main power for the sun and stars. Energy to keep the sun burning is produced by hydrogen atoms converting in to helium. The reason why hydrogen is able to turn in to helium is because the sun's core is at temperatures of about 10-15 million Kelvin. The energy released from this reaction is what keeps the sun burning which sustains life on Earth.

Nuclear fusion is also what makes the Hydrogen bomb (H-bomb) work/explode. It can also generate electricity.

[Explosion from a hydrogen bomb]