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  1. Definition

    1. Isotopes
    2. Forces Inside the Nucleus
    3. Radiation EmisionProcess
  2. Forms of Radiation

    1. Alpha Radiation
    2. Beta Radiation
    3. Gamma Radiation
    4. Background Radiation
  3. Application of Radioactivity

    1. Tracers
    2. Nuclear Reactor
  4. Risks of Radioactivity
  5. Refrences


Table of Contents


Generally, When we listen to the word radioactivity few things strikes our mind.  The main thing that strikes in our mind is Fukushima, Russia, China or some big countries with nuclear bombs or perhaps a nuclear waste site. This article focuses on what is radioactivity, how it works, forms of radiation, its application and risks.


Radioactivity is the emission of subatomic particles or electromagnetic waves from the nucleus as a means of staying stable. Before going to why atom emits radiation, I would like to explain few terms.



Isotopes of a certain element are the one with different nuclear formulae for the same element. And we know that the different elements, for each element have to have the same number of protons. In the case of isotopes, it has the same amount of protons but different amount of neutrons. This means that the same element can have different atomic mass because the proton number and atomic numbers remain same. 

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 When we look at the figure above, the figure of Helium 4 which is an isotope of Helium, it has two protons and two neutrons and its atomic mass is 4 and it has got two electrons orbiting around the nucleus.  Now, when we look it Helium 5, also an isotope of Helium, we can see 1 additional neutron inside the nucleus, and it still has two protons which makes it chemically same as Helium. Finally, those are the isotopes, which have a different neutron number of the same element.

  • Force Inside the Nucleus
               We learned from electricity that opposite charge attracts and like charges repel. And we also know that protons are positively charged and neutrons have no charge. So, if we take into account all of the protons in the atomic nucleus the question may arise, how does the nucleus stay intact without all the protons spontaneously repelling each other?  There is a strong nuclear force inside the nucleus which binds all the nucleons with other nucleons that are directly next to each other. Basically, strong nuclear force attracts protons with protons, attracts neutrons to neutrons and attracts protons with neutrons. It binds these nucleons together. Next force is the electromagnetic force, or we can call it the cool on a force which attempts to repel like charges from each other. Electromagnetic force has more dominance over the strong nuclear force, but the reason the strong nuclear force is called that is because it is so strong, much stronger than the electromagnetic force. The electromagnetic force is attempting to rip apart the nucleus, whereas the strong nuclear force is attempting to bind the nucleus together.

  • Radiation Emission Process