Since the 1950s, geologists have used radioactive elements as natural "clocks" for determining numerical ages of certain types of rocks. "Forms" means the moment an igneous rock solidifies from magma, a sedimentary rock layer is deposited, or a rock heated by metamorphism cools off.
It's this resetting process that gives us the ability to date rocks that formed at different times in earth history.
We'll learn about the different types of particles emitted during the process of radiation and look at some examples of radioactive elements and their uses.
Everything around us is made of elements, or different types of atoms.
Electrons float around the nucleus in a cloud-like structure.
The number of protons in an atom determines the identity of the element.
Alpha decay often creates unstable isotopes that undergo beta decay. Here, we'll go over a few key examples related to energy production, archaeology, and medicine.
Beta particles are a bit lighter than alpha particles, so they can go farther and penetrate materials deeper. In gamma decay no particles are released, but the isotopes formed by alpha and beta decay still have too much energy. These rays penetrate the farthest and can even go through a foot of concrete. Uranium (U)-235 is the main element used in nuclear power.If there are more or less, the isotope will have a different mass number than the original element.For example, normally carbon has 6 protons and 6 neutrons, giving it a mass number of 12.Each atom has a set number of protons and neutrons in the nucleus, but sometimes there are more or less neutrons than usual, which makes the element an isotope.Elements can be distinguished from isotopes by their mass number, or the total number of neutrons and protons in an atom.When living things die, they stop taking in carbon-14, and the radioactive clock is "set"!