What Are Radioactive Isotopes? | Properties of Matter | Chemistry | FuseSchool

Learn the basics about radioactive isotopes.

The identity and chemical properties of any atom are determined by the number of protons in its nucleus. As atoms get bigger and heavier, the nuclei get bigger and heavier and the protons need a “nuclear glue” to help hold them together.

Neutrons provide this glue and prevent the positive charges of protons from repelling each other, thanks to something called the strong nuclear force.

Elements can exist with slightly different numbers of neutrons. We call these isotopes of an element.

The number of protons in isotopes of one element will always be the same; this means that the element is unchanged and so will react chemically in exactly the same way.

There is often more than one stable isotope of an element. Much of the world around us is made up of stable isotopes. However, sometimes there aren’t enough neutrons in a nucleus or there are too many for it to be stable.

Nuclei will try to stabilise themselves. If there are too many protons or too many neutrons, the nucleus can spontaneously rearrange itself and throw out particles in the process. This is essentially what happens in radioactive decay.

Isotopes that have unstable nuclei are known as radioactive isotopes or radioisotopes. The more unstable a nucleus, the faster it will try to rearrange itself into a more stable state. This is known as radioactive decay.

Radioisotopes are often used in medicine to trace aspects of body chemistry or blood flow. Atoms of radioisotopes can act as “markers”, allowing chemists to follow how a reaction sequence occurs. Radioisotopes are also used in radiotherapy to kill malignant cancer cells.

SUBSCRIBE to the Fuse School YouTube channel for many more educational videos. Our teachers and animators come together to make fun & easy-to-understand videos in Chemistry, Biology, Physics, Maths & ICT.

This video is part of 'Chemistry for All' - a Chemistry Education project by our Charity Fuse Foundation - the organisation behind FuseSchool. These videos can be used in a flipped classroom model or as a revision aid. Find our other Chemistry videos here:

[abdulrahmanameralhamedi]

Thank you :) This video really helped me as a visual learner.

[williamdeng]

Hydrogen-1 also has a specific name: protium.

[kaseydarnell]

I love the visual analogy of what happens if there are too many neutrons. That made it make so much more sense! But I want to touch on you saying there are sometimes not enough. So what particles is the isotope getting rid of to become more stable? The protons?

[ifnaahassan]

This video is so understandable ! Good work ! 👌👏👏👏👩‍🔬☢ i am having so much trouble understanding this topic, but finally thanks to this video please make more of this!

[rapk]

today my chemistry teacher showed us this vid in our online zoom class...it helped a lot thank u so much

[vaidehithakare]

It means that the element's isotope having very large number of neutrons (82-92) releases their neutrons and it cause nuclear fission and high amount of energy is emitted so it causes the radiation. 💥

[cyperk]

thank you fuse school from Jordan again :)

[adityaitha]

very helpful for my chem F.A, Thank You.

[FURSTONERS]

Just to let you know, Hydrogen -1 is known as protium

[nickelacqua]

So can any element be unstable on the periodic table? I'm studying radiologic technology in school and in anatomy we briefly brushed on radioactive isotopes as medical tracers, but I always think about things like uranium, plutonium, like, are they just unstable by nature?

[itsAd.]

i really liked the way u explained how the stable state was achieved ; the woman and the box
good work keep learning and keep getting famous for ur good and hard work :)

[iresortan]

Thank you so much finally understand 😁

[shhhhhhhhh]

How does radioisotope exist if the nuclei just rearranges whenever it is unstable

[Stefin]

How can you tell if a element has too many or too little neutrons?

[Divyanshi-jiit]

Very good video, it cleared my concepts 👍

[DVIL]

I know this channel deserves 10 MILLION SUBSCRIBERS

[Divyanshi-jiit]

So do radioactive 'elements' and radioactive ' isotopes' have any difference.

[slickrick]

So does every element have a radioactive isotope? Or can be made to?

[raviagrawal]

It sounds like watching harry potter...Hahaha because of his voice


But this was more interesting...💞🤗
Very helpful thanks 🙌

[elleny]

Nice vid! I learned a lot from this! Plz do more videos about atoms!!!