Chalcogens (Group 6A Elements): Definition & Properties

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Halogens (Group 7A Elements): Definition & Properties

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

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:02 Chalcogens
  • 1:14 Properties the…
  • 3:09 Individual Elements…
  • 6:50 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: Julie Zundel

Julie has taught high school Zoology, Biology, Physical Science and Chem Tech. She has a Bachelor of Science in Biology and a Master of Education.

Some can kill you, some are useful, and one is vital to your survival. Welcome to the chalcogens! This lesson will list common properties, and will then share some uses and characteristics of these diverse Group 6A elements.


Although what I am about to tell you sounds like a story out of a movie, it really happened. In November 2006, a former KGB agent named Alexander Litvinenko became extremely sick after drinking tea with a former Russian agent. His hair fell out, the number of blood cells in his body declined, he had gastrointestinal problems such as nausea and vomiting, and then he eventually died. It was later determined he was poisoned by a Group 6A element called polonium (but more on Litvinenko later).

Polonium is one of five elements that belong to the chalcogens, or Group 6A elements, which include oxygen (O), sulfur (S), selenium (Se), tellurium (Te), and polonium (Po). Depending on where you're looking, this group can also be called Group 16 or Group VIA - all mean the same thing.

Elements are placed in groups, or the vertical columns on a periodic table, because they share certain properties. You may have noticed that oxygen is in the same group as polonium, and it would appear that a radioactive element that killed a former KGB agent would have very little in common with the air that keeps you alive, but they actually have a quite a few things in common.

Properties the Chalcogens Share

So, what do polonium and oxygen have in common? Oxygen, polonium, and the rest of the chalcogens all have six valence electrons; these are the outermost electrons, farthest away from the center of the atom. They give elements certain properties and help determine who the element can bond (or attach) with.

Most members of this group gain two electrons from another element so they can have eight valence electrons. Atoms are stable when they have eight valence electrons, so by gaining two, the chalcogens become stable. Electrons have a negative charge, and because most of the chalcogens gain two electrons, they get a -2 charge. This can also be referred to as a -2 oxidation state. An atom with a negative charge is called an anion.

So, the -2 oxidation state is the most common, but some of the other chalcogens can have other oxidation states. Sulfur, for example, can have oxidation states of +4 and +6. This means that sulfur can lose electrons and become more positive. Atoms that have a positive charge are called cations. And just to confuse you more, selenium, tellurium, and polonium can have oxidation states of +6! Because oxidation states can vary, just remember that -2 is the most common oxidation state for the chalcogens!

As you go down the group, the elements become more metallic. Oxygen and sulfur are nonmetals, selenium can be classified as a nonmetal or a metalloid, tellurium is a metalloid, and polonium is a metal. Nonmetals, metalloids, and metals all have different properties. For example, metals are good conductors of heat and electricity and are malleable (or bendy), whereas nonmetals tend to be poor conductors and are brittle. Metalloids have properties of metals and nonmetals.

Individual Elements Within the Chalcogens

Take a deep breath! That was a lot of information! And as you take a deep breath, imagine oxygen entering your mouth, traveling to your lungs, and then diffusing into your bloodstream, nourishing your cells, which leads us to our first chalcogen: oxygen. Not only is oxygen vital to your survival, but oxygen is everywhere! By mass, it makes up almost half of the Earth's crust and 90% of water. It makes up almost 21% of the Earth's atmosphere and it is the third most abundant element in the universe! But there's more! Almost 67% of your mass is oxygen. Wow!

So now we know oxygen is everywhere and is pretty important for your survival, but what else is there to know about this element? Well, you probably know that it is a colorless gas at room temperature and it is tasteless and odorless, but did you know that it is used in the refining of petroleum products, in steel and iron manufacturing, and as an ingredient in rocket fuel?

Another element you might already be familiar with from the chalcogens is sulfur. Have you ever been to a hot springs and noticed an unpleasant odor? You can thank sulfur for that! At room temperature, sulfur is a brittle, yellow solid that is odorless and tasteless, but when you combine it with hydrogen and form hydrogen sulfide you get that rotten-egg smell you may have smelled at a hot spring.

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