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Atoms and Radiation
Isotopes are atoms with the same number of protons but a different number of neutrons. A good
example of an isotope is carbon 12, carbon 13 and carbon 14. As you can see from the diagram
below, the proton number NEVER changes. This is because the proton number determines what
element the atom is, so if you were to change the proton number of carbon, it would no longer be a
carbon atom. However, the diagrams show the neutron number changing for different isotopes of
Most elements have different isotopes, but there are only a few stable ones. The rest are usually
radioactive meaning they decay into other elements whilst giving out radiation.
Radioactive substances give out radiation from the nuclei of their atoms. You've got to remember
that radioactive decay is a completely random process. It happens whenever. There are no special
circumstances where we can make it speed up or slow down. When a substance is giving out
radiation, it either gives out alpha particles, beta particles or gamma rays.
This happens all the time around us which is known as background radiation. Sometimes there are
naturally occurring unstable isotopes around us found in the air, in food, in rocks, etc. Radioactivity
also comes from the space in this way, mostly from the sun, which is more commonly known as
cosmic rays. There is a lot of background radiation from man-made sources for example, nuclear
accidents, or from nuclear weapons. The most important thing to remember is that radioactive
decay is always happening around us.
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For the course, you have to know the properties of each of the three types of radiation, so a quick
way to remember them is using the table below. It covers all the properties you need to know.…read more