Isotopes and nuclear radiation

• Alpha decay has a charge of +2. The mass number is 4 and the atomic is 2.
• Beta decay is an electron so has a charge of -1. The mass number is 0 and the atomic number is -1.
• Gamma decay is a wave transferring energy so has no charge.
• Neutron decay is a neutron so also has no charge. The mass number is 1 and the atomic number is 0.
• Nuclear radiation is when the nucleus of an atom emits radiation because it is unstable.
• Nuclear radiation happens because it has too many protons or too many neutrons, or if it is too large to be a specific element.
• Rutherford discovered alpha and beta radiation.
• Alpha particles are the same as a helium atom.
• When an atom emits alpha decay, the nucleus loses 2 protons and 2 neutrons.
• Beta particle is an electron emitted at high speeds from the nucleus.
• Beta particles are emitted from a nucleus when it has too many neutrons compared to protons. It is emitted when a neutron turns into a proton.
• Isotopes are different forms of the same element. They have the same number of protons (atomic number) but a different number of neutrons (mass number).
• All elements have isotopes, but there are usually only one or two stable ones. Unstable isotopes tend to decay into other elements and give out radiation.
• Radioactive substances spit out one or more types of ionising radiation from their nucleus. They can also release neutrons to rebalance their atomic and mass number.
• Ionising radiation is radiation that knocks electrons off atoms, creating positive ions. The ionising power is how easily it can do this.
• Alpha particles dont penetrate far and are stopped by skin or paper. They can only travel a few cm in the air but are strongly ionising.
• Beta particles penetrate moderately far and can be stopped by a sheet of aluminium. They can travel a few metres in the air and are moderately ionising.
• Neutron particles penetrate far into materials and can be stopped or reduced by water. They can travel a few kilometres in the air and have low ionising.
• Gamma rays are waves of electromagnetic radiation released by the nucleus. They penetrate far into materials without being stopped and will travel several kilometres in the air. They can be absorbed by thick lead or concrete and are low ionising.