# What is a Quark? - Definition, Structure & Uses

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Galaxy Formation: Spiral, Elliptical & Irregular Galaxies

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

Replay
Your next lesson will play in 10 seconds
• 0:04 Quarks Defined
• 1:06 Quarks: A Closer Look
• 3:32 Lesson Summary
Save Save

Want to watch this again later?

Timeline
Autoplay
Autoplay
Speed Speed

#### Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Sergey Segal

Sergey has a Masters in Biomedical Engineering and has taught science and mathematics courses at the University of Wisconsin-Madison.

Quarks are fundamental particles that are used by scientists to explain different types of phenomena. Learn more about them, subsequently testing your knowledge with a quiz.

## Quarks Defined

Imagine taking a block of butter and cutting it in half. After doing that, you take one of the resulting pieces and cut that one in half, and then do it again for the smaller pieces that follow, over and over. For the purposes of this thought experiment, your knife is infinitely thin, and you can keep going for an indefinitely long time. Initially, you will see smaller and smaller chunks of butter, until they become invisible to the naked eye. As you keep going, you will get down to the level of molecules, individual atoms, and finally subatomic particles.

You may be familiar with protons, neutrons, and electrons, which are the basic constituents of atoms. The protons and neutrons make up the nucleus of an atom, while the electrons orbit around this nucleus. However, even protons and neutrons are made up of more elementary particles, called quarks, which you can think of as tiny entities that are among the most basic constituents of all matter.

Let's proceed to take a closer look at these particles.

## Quarks: A Closer Look

There are six types, also known as flavors, of quarks: up, down, strange, charm, bottom, and top. These flavors differ based on mass and electric charge. By the way, the electric charge property I just mentioned is the same one that exists in electric circuits or that causes a hair brush to attract small strips of paper after you brush your hair with it. The 'up', 'charm', and 'top' quarks have a positive charge of +2/3, while the 'down', 'strange', and 'bottom' quarks have a negative charge of -1/3. Don't worry about the numbers, but remember that opposite charges (positive-negative) attract, while like charges (positive-positive or negative-negative) repel each other.

The masses of quarks, from heaviest to lightest, are as follows: top (heaviest), bottom, charm, strange, down, and up (lightest). Keep in mind that since we are talking about elementary particles, you can think of their masses as just another property that characterizes them. After all, you can't really weigh quarks on your scale at home.

Another property of quarks is color, also referred to as color charge. In order to satisfy the Pauli Exclusion Principle, which asserts that no two quarks can exist in the same quantum state at the same time, the property of color was ascribed to quarks. Three colors could be assigned to individual quarks, and a common color scheme is red, green, and blue.

For the purposes of our discussion, it's important to mention that every quark has an antimatter particle associated with it, called an antiquark. You can think of antiquarks as quarks with opposite electric and color charges.

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

### Register to view this lesson

Are you a student or a teacher?

#### See for yourself why 30 million people use Study.com

##### Become a Study.com member and start learning now.
Back
What teachers are saying about Study.com

### 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.