Stars are formed from interstellar material. Describe how a star of similar mass to our Sun is formed from a nebula.

Commercial nuclear power stations use nuclear fusion rather than nuclear fusion to generate electricity.

This graph shows how the probability of a nuclear fusion reaction changes with core temperature (in million Kelvin):

Draw on this

Using the graph and your scientific knowledge, compare the nuclear processes of fission and fusion, and explain why commercial power stations currently only use nuclear fission.