Introduction

It’s a question that has been asked since the dawn of time: What is the most common element in the universe? It’s difficult to answer, but we’re here to try.

The universe isn’t just a big, empty void. It’s full of the matter! We’re all familiar with the periodic table of elements, which lists all of the elements we’ve discovered so far here on earth (although new ones are still being added). But what about those elements that have been introduced into our universe since its creation? Since there’s no way to travel back in time to observe them being forged in the fires of exploding stars and planets, we can only make educated guesses as to their existence and abundance.

The most common guess is that hydrogen—the lightest element on Earth—was also the most common element when our universe first came into existence. And it was made even more common by the fact that its atoms had not yet begun interacting with other atoms or molecules to form compounds such as water or organic carbon compounds. This is because early stars were mostly composed of helium and hydrogen.

It is said that Hydrogen and Helium make up about 99% of the atmosphere.

Hydrogen

Hydrogen is the most abundant element in the universe. In fact, it’s the most common element there is. As a matter of fact, hydrogen makes up about 70% of all atoms found in nature.

It also happens to be one of the most abundant elements on Earth. So, you can’t escape it! Hydrogen is even present inside our bodies because we are made up of cells that need water and oxygen to survive (you learned those things from school). And guess what? Both water and organic matter contain a lot of hydrogen!

Helium

Helium is the second most common element in the universe, and it’s also one of the five non-metals that make up around 28% of Earth’s atmosphere.

Helium was first discovered by a French astronomer named Jules Janssen in 1868, but it wasn’t until much later that scientists understood how important helium was. It’s a noble gas, meaning it doesn’t react with other elements or compounds at all—it’s completely inert.

The element has many uses in modern-day life, including scientific research, medicine, manufacturing, and entertainment such as balloons or blimps (such as those used at sporting events). That is because helium is lighter than air (that’s not true for most other gases), you’ll often find it in balloons!

It’s used as a coolant for nuclear reactors and can be found in MRI machines to function properly with electromagnetism by acting as a coolant.

Oxygen

After hydrogen and helium, oxygen is the third most frequent element in the universe.

You may have heard that carbon is the most common element in the universe. But you’re probably more familiar with oxygen, which is everywhere on Earth.

This isn’t surprising when you consider that it’s also the most abundant element in Earth’s crust, atmosphere, and water (though not in equal measure).

In the human body, oxygen contributes to a vast majority of organic compounds that makes us living beings. There are several compounds that contain oxygen, which makes it one of the most versatile substances on Earth.

Carbon

After hydrogen, helium, and oxygen, carbon is the fourth most abundant element in the universe.

It makes up more than three-quarters of Earth’s crust, as well as human and animal organisms. Carbon has a unique combination of properties that make it ideal for life: it is a solid at room temperature but soft enough to be cut by scissors. It is stable at room temperature for millions of years (unlike many other elements); and capable of forming four bonds with other atoms instead of three like most elements.

Because carbon has these properties—and because life requires them—it is necessary for all living things on this planet.

Conclusion

You might be surprised to learn that hydrogen and helium are the most common element in the universe.

Given the sheer number of galaxies and stars in space, the most common element in the universe is no doubt hydrogen. However, the second most common element is helium.

That being said, the first two elements are still the main stars of the periodic table—hydrogen and helium account for more than 99 percent of every object in the observable universe.