nuclear fusion and fission

nuclear fission

is the splitting of a large and unstable nucleus (eg uranium and plutonium)

what causes fissions to happen

spontaneous fissions are rare and so usually for fission to occur the unstable nucleus must first absorb a neutron

what happens when nucleus undergoes fission

splits into two smaller nuclei, roughly equal in size and emits two or three neutrons plus gamma rays and energy is released.

what do all of the fission products have

kinetic energy

what can the neutrons emitted be used for

can go on to start a chain reaction

what can scientists do with fission chain reaction

can control the fission chain reaction and use energy released to generate electricity in nuclear reactors

what causes the explosion in a nuclear weapon

explosion in a nuclear weapon is caused by an uncontrolled fission chain reaction

nuclear fusion

is the joining of two light nuclei to form a heavier nucleus. some of the mass of the nuclei can be converted into energy which is released as radiation- not a chain reaction