What is the difference between fission and fusion

During fission, a larger nucleus is broken down into smaller nuclei. During fusion, smaller nuclei are joined to create a larger nucleus.

Explanation: For gradpoint ;)

convex lenses are thicker at the middle. rays of light that pass through the lens are brought closer together (they converge). a convex lens is a converging lens. when parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus.