Login

Types of Radioactive Decay and Their Effect on the Nucleus

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Balancing Nuclear Equations & Predicting the Product of a Nuclear Reaction

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:06 Nuclear Radiation
  • 1:26 Nuclear Notation
  • 3:10 Alpha Decay
  • 4:28 Beta Decay
  • 5:48 Gamma Decay
  • 7:16 Lesson Summary
Add to Add to Add to

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Login or Sign up

Timeline
Autoplay
Autoplay
Create an account to start this course today
Try it free for 5 days!
Create An Account

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Kristin Born

Kristin has an M.S. in Chemistry and has taught many at many levels, including introductory and AP Chemistry.

What is meant by the term 'radioactive'? In this lesson we will break down the three main types of nuclear decay particles and discuss their composition, their effect on the nucleus, and their applications.

Introduction

What images come to mind when you hear the words 'nuclear radiation'? Most likely these words conjure up a graphic scene of three-eyed fish and glowing green ooze. There are many misconceptions flying around out there when it comes to nuclear radiation, and the best thing you can do is educate yourself on the subject. Who knows; someday you may be voting on whether a nuclear facility is built near you.

Nuclear Radiation

Did you know that less than 1% of all the radiation you are exposed to comes from the nuclear industry? Most of it comes from natural sources like rocks. You are even a little radioactive! Nuclear radiation comes from all kinds of different places. There is natural radiation from the sun, water, and even bananas. There are also man-made sources of radiation, like nuclear reactors, certain types of medicine, and the smoke detectors in your home.

What exactly is radiation, and how damaging is it? The amount of danger nuclear radiation presents depends on which type of radiation it is. Today we will be discussing the three most common types of radioactive decay: alpha, beta, and gamma. Before we do that, we'll first do a quick review of the nuclear particles you should be familiar with along with their nuclear notation.

With these carbon isotopes, the 6s represent the atomic number and the top number is the mass number
Atomic Number Description

Nuclear Notation

As you may recall, the two particles that are found in the nucleus are the protons and neutrons. Because the atomic number of an element is the number of protons its atom has, a proton essentially has an atomic number of 1. It also has a mass number of 1 because its mass is almost exactly 1 amu. These two numbers are so important that sometimes they are included in certain notation. For example, when we are distinguishing the difference between three carbon isotopes, notice they all the sixes on the lower left of the symbol. Those sixes represent the number of protons (or the atomic number). They all have the same atomic number because they're all carbon. The top number is the mass number, which is the number of protons and neutrons, because both protons and neutrons have a mass of 1. Each of these three isotopes has the same number of protons but different numbers of neutrons.

Particles in the nucleus can also be represented by this nuclear notation. Going back to the proton example, its atomic number of 1 and mass number of 1 can be represented a couple of different ways - sometimes as a p with the atomic number on the bottom and the mass number on the top. Sometimes a little + is put as a superscript to the p, indicating its charge. And sometimes it's even represented as a hydrogen nucleus with an H instead of a p, because most hydrogen atoms have an atomic number of 1 and a mass number of 1. When using nuclear notation, the neutron is almost always represented as a 1, 0, and n, the 1 indicating the mass number, the 0 showing the atomic number, and the n symbolizing that the particle is a neutron. Later on, you will see why representing particles like this helps us keep track of everything.

Alpha Decay

Alpa particles can be easily blocked by air, clothes and your skin
Alpha Particle Easily Blocked

Now let's move on to the most common types of nuclear decay. The first is alpha decay. In alpha decay, the nucleus emits an alpha particle, or a particle containing two protons and two neutrons. The nucleus is said to decay, or change into one that is a little lighter, one with four less particles. An alpha particle can be represented a couple different ways - first, with 4, 2, and alpha symbol, the 4 representing the mass number (the number of protons plus neutrons) and the 2 representing the atomic number (the number of protons). Instead of the alpha symbol, the symbol for helium (He) is sometimes used because it's really just a helium nucleus.

Alpha particles are relatively heavy and quite slow-moving. It is for this reason that they can be blocked very easily by air, paper, clothing, and even your skin. Ingesting an alpha-particle emitter would be dangerous because your inner tissues don't provide the protection that your skin does and the alpha particles could cause some tissue damage. One of the main sources of alpha particles is the element radon, which is a gas found in many rocks. If a lot of radon is inhaled, it can get in your lungs and damage lung tissue. Some homes are even equipped with radon detectors to warn you if the levels are getting too high.

Beta Decay

One way that beta decay is represented
Beta Decay Represented

Next up is beta decay or beta-minus decay. Beta decay occurs when a neutron turns into a proton and an electron is emitted. It can also be represented a couple of different ways. Both have a 0 and -1, and either a beta symbol or an e is shown. The reason an e is used is because a beta particle is really just a high-energy electron being emitted from a nucleus. Beta decay occurs when the nucleus contains too many neutrons. For example, tritium, the super-heavy isotope of hydrogen, has 2 neutrons and 1 proton (the most common form of hydrogen contains no neutrons). This tritium isotope is very unstable, and it will likely undergo beta decay, turning into a helium atom because one of its neutrons transforms into a proton and releases an electron. Unlike alpha particles, beta particles are high-energy and very light. They can travel through paper and certain types of clothing, but they are usually stopped by the first couple layers of your skin. To shield beta particles, a sheet of aluminum is needed. They can cause tissue damage, which is both good and bad. Damaging healthy cells can cause cancer; however, when beta particles damage cancer cells, they can provide a cure for cancer.

To unlock this lesson you must be a Study.com Member.
Create your account

Register for a free trial

Are you a student or a teacher?
I am a teacher
What is your educational goal?
 Back

Unlock Your Education

See for yourself why 30 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back

Earning College Credit

Did you know… We have over 95 college courses that prepare you to earn credit by exam that is accepted by over 2,000 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it free for 5 days!
Create An Account
Support