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

Summary

This lesson from FuseSchool explores why some isotopes are radioactive. It explains that the identity and chemical properties of an atom are determined by the number of protons in its nucleus. As atoms grow larger, neutrons act as a "nuclear glue" to stabilize the nucleus, which can vary in neutron number among isotopes. Unstable isotopes, known as radioisotopes, can undergo radioactive decay, a process where the nucleus rearranges itself to achieve stability. The video also highlights practical applications of radioisotopes in medicine and chemistry, such as using technetium-99 for medical imaging and in radiotherapy to treat cancer.

Highlights

• Atoms are determined by the number of protons in the nucleus. 🌟
• Neutrons provide 'nuclear glue' to stabilize the nucleus. 🧲
• Isotopes differ in neutron numbers but not in chemical properties. ⚛️
• Too many or too few neutrons lead to instability, causing radioactive decay. 🌀
• Radioactive isotopes are key tools in medical imaging (e.g., technetium-99) and cancer treatment. 🩺
• Lighter hydrogen isotopes are stable, while heavier ones like tritium are radioactive. 💧

Key Takeaways

• Isotopes of an element have the same chemical properties because they contain the same number of protons. 🎯
• Neutrons act as a nuclear glue, preventing protons from repelling each other. 💪
• Unstable isotopes are called radioactive isotopes or radioisotopes. 🚀
• Radioactive decay is the process of radioactive isotopes attempting to become stable. 🌟
• Radioisotopes have practical applications in fields like medicine for imaging and cancer treatment. 💉
• Technetium-99 is a commonly used medical radioisotope tracer. 🏥

Overview

Radioactive isotopes, or radioisotopes, have nuclei that are unstable and prone to radioactive decay. This interesting process occurs when the nucleus rearranges itself in an attempt to become stable by shedding excess particles. It’s the quirk of having too many or too few neutrons, kind of like trying to juggle too many tasks at once and dropping some! 🌌

As neutrons act as a kind of glue holding the nucleus together, varying numbers of these gluey particles create isotopes. Some are stable, happily going about their business, while others are just a little too heavy or too light to keep things together. They end up releasing particles to find balance, much like trying to carry a too-heavy stack of boxes until you can comfortably manage them. 📦

The practical side of radioisotopes shines in fields like medicine and science. For example, technetium-99 is used as a tracer in medical imaging, stealthily helping doctors see inside the body. Radioisotopes are also used in treatments, taking on harmful cancer cells like little warriors on the battlefield of health! 🎯

Chapters

• 00:00 - 00:30: Introduction to Radioactive Isotopes This chapter introduces the concept of radioactive isotopes. It suggests referring to another lesson on why atomic masses aren't whole numbers to aid understanding. The chapter discusses that the identity and chemical properties of an atom depend on the number of protons in its nucleus. As atoms increase in size and weight, so do their nuclei.
• 00:30 - 01:00: The Role of Neutrons and Isotopes Neutrons play a crucial role in the nucleus by acting as a 'nuclear glue' that holds protons together, preventing them from repelling each other due to their positive charge. This is made possible by the strong nuclear force. Elements can have different numbers of neutrons, which are known as isotopes. Isotopes are especially common in heavier elements, where a substantial number of neutrons are necessary to maintain the integrity of the nucleus.
• 01:00 - 02:00: Examples of Hydrogen Isotopes The chapter titled "Examples of Hydrogen Isotopes" discusses the different isotopes of hydrogen, which include hydrogen-1, hydrogen-2 (deuterium), and hydrogen-3 (tritium). The chapter explains that these isotopes differ in the number of neutrons, with hydrogen-1 having 0 neutrons, hydrogen-2 having 1 neutron, and hydrogen-3 having 2 neutrons. It highlights that tritium is the heaviest of the isotopes due to its larger mass number, and emphasizes that all these isotopes contain a single proton.
• 02:00 - 02:30: Stability and Radioactive Decay The chapter titled 'Stability and Radioactive Decay' explains the concept of isotopes and their stability. It emphasizes that an element remains chemically the same even if it has different isotopes. The world is largely composed of these stable isotopes. However, instability arises when a nucleus has too few or too many neutrons, leading to radioactive decay. This idea is analogized to a person carrying boxes to illustrate the concept of balancing neutrons for stability.
• 02:30 - 03:30: Understanding Radioactive Decay The chapter "Understanding Radioactive Decay" uses the analogy of carrying boxes to explain how nuclei stabilize themselves. Just like a person will keep dropping boxes until they reach a manageable amount, nuclei will rearrange themselves by emitting particles if they have too many protons or neutrons, achieving a stable state.
• 03:30 - 04:30: Applications of Radioisotopes in Medicine The chapter explains the concept of radioactive decay and its relevance to radioisotopes in medicine. Isotopes with unstable nuclei are termed radioactive isotopes. Tritium is given as an example of a radioisotope of hydrogen. The lecture discusses the process of these isotopes transitioning to more stable forms through radioactive decay, which is an important concept in medical applications.
• 04:30 - 05:00: Summary of Isotopes and Radioisotopes This chapter covers the uses of isotopes and radioisotopes, particularly focusing on their application in medicine and chemistry. Radioisotopes like technetium-99 are highlighted for their role as medical tracers, which are injected into the bloodstream to assist with medical imaging and diagnostics. The chapter also touches upon the use of tracers in chemistry to track and understand chemical reactions.

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

• 00:00 - 00:30 this lesson looks at why some isotopes are radioactive you may wish to refer to the lesson why aren't all atomic masses whole numbers to help you understand this video the identity and chemical properties of any atom are determined by the numbers of protons in its nucleus as atoms get bigger and heavier the nuclei get bigger and heavier and the
• 00:30 - 01:00 protons need a sort of 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 and we call these isotopes of an element it is particularly common for heavier elements where a lot of neutrons are required to hold the nucleus together
• 01:00 - 01:30 but smaller and lighter examples include the isotopes of hydrogen hydrogen 1 hydrogen 2 also called deuterium and hydrogen 3 also known as tritium are the three isotopes of hydrogen they have 0 1 and 2 neutrons respectively tritium is the heaviest isotope of hydrogen as it has a larger mass number note that in each of these isotopes there is a single proton
• 01:30 - 02:00 and this means that the element is unchanged and that's the important point it is still hydrogen and will react chemically in exactly the same way there is often more than one stable isotope of an element in fact much of the world around us is made up of stable isotopes however sometimes there aren't enough neutrons in a nucleus or there may be too many for it to be stable an analogy is a person carrying boxes
• 02:00 - 02:30 if you try to carry too many boxes you'll end up dropping some and if you continue you'll keep dropping boxes until you reach a manageable amount this is your stable state and nuclei behave in a similar way and they will try to stabilize themselves if there are too many protons or too many neutrons the nucleus can spontaneously rearrange itself and throw out particles in the process
• 02:30 - 03:00 this is essentially what happens in radioactive decay isotopes that have unstable nuclei like this are known as radioactive isotopes or radioisotopes in our hydrogen examples tritium are unstable and are hence radioisotopes of hydrogen the more unstable a nucleus the faster it will try to rearrange itself into a more stable state and another name for this process is radioactive decay
• 03:00 - 03:30 radioisotopes are often used in medicine to trace aspects of body chemistry or blood flow for example a small amount of the radioisotope technetium-99 may be injected into the bloodstream to show up on medical imaging and x-rays and this is known as a medical tracer tracers can be used by chemists to understand how a reaction works atoms of radioisotopes can act as markers allowing chemists to follow how
• 03:30 - 04:00 a reaction sequence occurs and of course radioisotopes are also used in radiotherapy to kill malignant cancer cells so as you can see isotopes are important in modern science and so we'll finish with a summary of the key points isotopes of the same element have the same chemical properties some isotopes are stable
• 04:00 - 04:30 isotopes that are unstable are radioactive radioactive isotopes are also known as radioisotopes radioisotopes can be used as traces or markers in chemistry and medicine and they are also used to kill cancer cells you