What Is an Ion?

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: What is a Solvent? - Definition & Examples

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

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:00 Definition of an Ion
  • 0:47 Formation and Types of Ions
  • 2:19 Examples of Ions
  • 4:14 Lesson Summary
Save Save Save

Want to watch this again later?

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

Log in or Sign up

Speed Speed

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Adrianne Baron

Adrianne has a master's degree in cancer biology and has taught high school and college biology.

Learn what an ion is and how it forms. We will look at some common ions and get to know the terms for the two types of ions. Take the quiz at the end to see how well you understand the lesson.

Definition of an Ion

Let's recap a few things you probably learned a long time ago. There are 3 subatomic particles that are found in the atoms of an element. They are the positively charged protons, negatively charged electrons, and neutrons, which have no charge. Elements normally have the same number of protons and electrons in each of its atoms. This being the case, the atoms of the elements are neutral, meaning that they don't have a net positive or negative charge.

There are some instances when an atom may have a positive or negative charge. When the atom has a charge, it is now known as an ion. Atoms will pick up or lose electrons, which creates this charge. Electrons move around to reach the goal of having a full outermost shell within the atom in order to be stable.

Formation and Types of Ions

The positively charged protons always remain the same in an atom. The negatively charged electrons, however, can move from one atom to another. Ions form when an atom loses or gains electrons. Let's look at this a different way for a minute. You are making a decision, and you are weighing out your pros and cons. The pros are positive, and the cons are negative. You are at a point in your list where you have the same number of pros as cons. This would be the same as how the atom normally occurs.

Suddenly, you think of another con to add to the list. Now you have 1 more con than you do pros. This makes the decision more negative than it is positive. This same thing happens when an atom gains an electron. It now has more negatively charged particles than it does positively charged particles. A negatively charged atom has now become an ion known as an anion.

After thinking about things even more, you realize that you already have a solution for the con you just added, so you erase it. You are back to being even on your decision. Then you see that another con has also been resolved so you erase it as well. Now you have 1 more pro than you do cons. At this point, the decision is more positive than it is negative. This is the same as the neutral atom losing a negatively charged electron. It now has more positively charged particles than negatively charged ones. A positively charged atom that has now become an ion is known as a cation.

Examples of Ions

There are several commonly occurring ions. Let's look at some common anions first. Hydrogen usually has 1 proton and 1 electron. It sometimes gains an electron so that it has 2 electrons and still just 1 proton. It is now an anion named hydride.

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

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 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? 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 risk-free for 30 days!
Create an account