Two Main Forces Involved In Nuclear Fusion

The two main forces involved in nuclear fusion are the electromagnetic force and the strong nuclear force. The repulsive electromagnetic force between positively-charged nuclei is long range but relatively weak while the nuclear force is short range but much stronger. When the two nuclei are far enough apart, the repulsive electromagnetic force dominates, holding the nuclei apart. As the two nuclei get closer the electromagnetic repulsion gets stronger and more difficult to push the nuclei together. When the two nuclei approach and get closer to each other, the nuclear force dominates and the two nuclei fuse together to form a new nucleus. This requires a lot of pressure, provided by gravity caused by mass to push nuclei together in short-range
that they fuse together. Fusion is not normally possible due to the strongly repulsive electrostatic forces between the positively charged nuclei prevent them from getting in close enough proximity to collide and therefore for fusion to occur. In certain conditions the nuclei can overcome the electrostatic forces to a point where they can come within close range of each other, then the attractive nuclear force outweighs the repulsive (electrostatic) force, binding the protons and neutrons together in atomic nuclei. These certain conditions occur when the temperature increases causing the ions to move faster reaching speeds which can bring the ions close together. The nuclei will then fuse in the solar core, causing a release of energy.