Hydrogen: Properties & Occurrence

Instructor: Laura Foist

Laura has a Masters of Science in Food Science and Human Nutrition and has taught college Science.

Hydrogen is the most commonly found element in the universe. In this lesson we will learn about properties of hydrogen, from its place on the periodic table of elements to its physical and chemical properties.

Hydrogen on Earth and Universe

The air all around us, the water we drink, the cells of our body, a plastic cup, and many other objects all around us; all of these have one thing in common - they contain hydrogen. Hydrogen is the most common element in the universe. It is one of the elements that makes up every organic compound and is also a part of many inorganic compounds.

Despite the fact that it is the most common element, it is extremely rare to find on its own on earth, but is very common to find in outer space. Since hydrogen is so light, free hydrogen can easily escape the atmosphere.

Hydrogen is also very reactive, so if it does not escape the atmosphere it reacts with other compounds and can no longer be found free. So to naturally find hydrogen on earth we must look for it in other compounds. It is part of many reactions and many compounds.

Hydrogen in the Periodic Table

Hydrogen is the first element on the periodic table. The periodic table is organized according to atomic weight, meaning hydrogen is the lightest of the elements. It is in period number 1 and group number 1, and is classified as a non-metal. A period on a periodic table describes a row horizontally across the table; a group, also called a family, on a periodic table describes a column vertically up and down the table.

Hydrogen is frequently put into group 1 and period 1 on the periodic table
Periodic table

Hydrogen is interesting in its placement on the periodic table because it is actually in its own group and period. It doesn't really follow the same trends as other elements do within groups and periods. Most of the time it is placed in group 1 with the alkali earth metals, but it could also be placed in group 18 with the halogens. It can lose an electron which makes it similar to the alkali earth metals, but it can also gain an electron making it like the halogens.

Periods aren't usually too important, as trends are not always consistent across periods on the periodic table. In hydrogen's case, it is placed into period 1 with helium. The only consistent trend across periods is that the atomic number increases from left to right. This is the case from hydrogen to helium, even though these two elements are otherwise very different.

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