Radioactive Decay, Nuclear Fission and Nuclear Fusion
When elements undergo radioactive decay the atoms of one element are changed into the atoms of another element when an alpha or beta particle is emitted from an unstable nucleus. When a nucleus disintegrates and emits an alpha particle it is alpha decay, the alpha particle emitted contains two protons and two neutrons which is equivalent to a helium nucleus being released. Alpha decay occurs because there are too many protons, which causes excessive repulsion within the nucleus, and in an attempt to reduce the repulsion the helium nucleus will be emitted from the atom. The helium nucleus is constantly colliding with the walls of the nucleus and due to its mass and energy it will tunnel out of the nucleus.
Beta decay occurs when there are too many neutrons compared to protons, which makes the nucleus unstable. In basic beta decay the neutron is turned into a proton and an electron, the electron is then emitted. The resulting element will have one more proton than the original element.
Beta decay also happens when the neutron to proton ratio is too small, this happens by positron emission. In this beta decay a proton is turned into a neutron and a positron, the positron is then emitted from the nucleus. When the proton to neutron ratio is too small there can also beta decay by electron capture where an electron is captured by the nucleus and turns a proton into a neutron.
Nuclear Fission reactions differ from natural radioactive decay both in how the reactions are started and also the products that are formed. Radioactive decay happens when the nucleus is unstable due to the number of protons and neutrons within the nucleus. The nucleus is made stable by the emission of particles from the decaying nucleus. In nuclear fission a neutron is fired at an atoms nucleus, if the neutron has given the atom enough energy it will enter an excited state and begin to...
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