Uses of radiation dating
Radioactivity has a wide range of uses, including nuclear power, in medicine, and in dating organic and geological samples.
It is also potentially dangerous, as high-energy particles and radiation can damage and kill cells, and alter DNA, causing cancer.
These high-energy electrons are known as beta rays, or beta particles.
Half-life applies to a sample of any size, from a microscopic quantity to all the atoms of that type in the universe.
Different radioactive isotopes vary widely in their half-lives, which range from a few seconds, in the case of astatine-218, to billions of years for uranium-238.
Beta decay occurs when a nucleus has too many neutrons for its number of protons.
In this process, a neutron, which is electrically neutral, spontaneously changes into a positively charged proton by emitting a negatively charged electron.
The best-known uses of radioactivity are perhaps in nuclear power stations and in nuclear weapons.