Hydrogen: Everything You Need to Know

Bryan Carmichael
Feb 10, 2021
5 min read

Updated: Apr 6, 2021

Note: This is the second article of a new series I'm writing titled Everything You Need to Know. If you enjoyed this article, be sure to check out my previous article and stay tuned for all future articles.

Introduction

Hydrogen. The first element in the periodic table. The most common element in our universe. Hydrogen is such a vital element in our society, planet and universe, but what must we know about it?

For starters, what do you know about it? Does it make water? What do we as a society know about it? That it’s lighter than air and makes great rocket fuel?

Here are some of the weird and wonderful things about arguably one of the more interesting elements on the periodic table.

What About the Smallest, Simplest Element in the Periodic Table?

Hydrogen is a colourless, odourless gas at room temperature. It is non-toxic and highly combustible. It has a freezing point of -259.14 ºC and a boiling point of -252.87 ºC. Discovered in 1766, hydrogen was one of the first substances formed after the big bang, currently making up 75% of our universe. Our bodies are around 10% hydrogen, our earth's crust is about 0.15%, and the ocean is about 11%.

Hydrogen lies in Group 1 (first column) as well as Period 1 (first row) on the periodic table. Its relative atomic mass, as well as atomic number (number of protons), are both 1. This makes it the first element, the smallest element in size, and the simplest element in electronic configuration.

Hydrogen has one electron shell, which is one electron too many as well as one electron too few to be stable, meaning its reactivity level is very high. Hydrogen in its natural state is diatomic, meaning it has two hydrogen atoms (covalently) bonded together to form one molecule of hydrogen gas.

Hydrogen is lighter than air, meaning that if we released hydrogen into the air, it would float into space and never come back.

Fun fact: Hydrogen is the only element in the periodic table that doesn’t have any complete electron shell.

Fun fact: As hydrogen is one too many as well as one too few from completing its outer electron shell, it can exist in an ionic state as a cation and an anion — it is the only element in the periodic table that can do so.

Three Natural Isotopes

While hydrogen in manmade forms has up to seven isotopes, hydrogen has three naturally occurring isotopes. Protium (H), or hydrogen-1, is the most common form of hydrogen, accounting for 99.98% of the world’s supply. It has an atomic mass of 1, meaning it has one proton, one electron and no neutrons.*

Deuterium (D), or hydrogen-2, is far less common than protium. Approximately 0.02% of the world’s hydrogen is deuterium. Its name originates from the Greek word deuteros, meaning ‘second’. It is called this because it has an atomic mass of 2, as there is one proton, one electron and one neutron present.

Tritium (T), or hydrogen-3, is so rare to find in nature that it’s only detectable in trace amounts. It accounts for about 10^(-18)% (0.000000000000000001%) of the world’s hydrogen. It has an atomic mass of 3, with one proton, one electron and two neutrons. It is the only naturally occurring isotope of hydrogen that is radioactive.

Fun fact: Hydrogen is the only element that has names for its naturally occurring isotopes.

* Protons have a relative mass of 1

* Neutrons have a relative mass of 1

* Electrons have a negligible mass (0)

Applications for Hydrogen

There are many uses for hydrogen and its isotopes, the most commonly known to be the production of water. Two hydrogen atoms covalently bond with one atom of Oxygen to make water (in the liquid form), or dihydrogen monoxide (in all forms). Here is a list of some lesser known uses of hydrogen.

Methanol production
Rocket fuel*
Welding
Hydrochloric acid production
Filling hydrogen balloons
Cryogenics and the study of superconductivity (as it has a freezing point just above absolute zero)

*Fun fact: the Challenger space shuttle, that blew up at take off, was caused by hydrogen in the fuel tanks combusting and exploding.

Nuclear Fusion

Hydrogen atoms at extremely high temperatures can fuse together into one atom with a heavier nucleus. Hydrogen is favoured for this nuclear fusion because of its weak positive charges, meaning less resistance to overcome. Specifically, deuterium atoms are ideal because when combined, they create a nucleus with two protons and two neutrons, the nucleic configuration of a whole new element: Helium.

Heavy Water

When two deuterium atoms bond with an oxygen atom to form a water molecule, it is known as ‘heavy water’ (D2O) and is 11% denser than regular water. It has a higher freezing point than protiated water (H2O) of 3.82 degrees celsius and a higher boiling point of 101.4 degrees celsius. The odds of finding a naturally occurring heavy water molecule is 1 in 40960000 (6400^2 as 1 in every 6400 hydrogen atoms is deuterium). Heavy water is stable as deuterium is stable.

Hydrogen-Deuterium Oxide - (Semi-Heavy Water)

When one protium atom and one deuterium atom bond with an oxygen atom to form a water molecule, it is known as ‘semi-heavy water’ (HDO). It has a higher freezing point than protiated water (H2O) of 2.04 degrees celsius and a higher boiling point of 100.7 degrees celsius. The odds of finding a naturally occurring semi-heavy water molecule is 1 in 3200 (as 1 in every 6400 hydrogen atoms is deuterium). Semi-heavy water is stable as deuterium and protium are both stable.

Tritiated Water - Super-Heavy Water

When two tritium atoms bond with an oxygen atom to form a water molecule, it is known as ‘superheavy water’ (T2O or 3H2O). It has a higher freezing point than protiated water (H2O) of 4.48 degrees celsius and a higher boiling point of 101.5 degrees celsius. As tritium is radioactive, tritiated water is therefore radioactive. One use for tritiated water is to determine the water content in your body. This is because when you consume tritiated water, it enters all of your body’s water compartments in equal amounts, therefore the amount of tritiated water you urinate afterwards will be proportional to the tritiated water in the rest of your body’s water compartments, from there you can determine the amount of water in each of your body’s water compartments.

Conclusion

Feel like you know more now? Hydrogen is a beautiful element, with so many unique properties. Which was your favourite? The fact that it has isotopes with names? The fact that it doesn’t have any complete electron shell? The fact that it makes great rocket fuel?

My personal favourite thing about hydrogen is the physical and chemical properties of its isotopic variations of water (i.e. heavy water). It’s fascinating to me because, of the amount of water you’ve drank over your lifetime, it’s very possible that you have drunk molecules of heavy and semi-heavy water! Try and swallow that.

Bibliography

Britannica. "Hydrogen | Properties, Uses, & Facts." Encyclopedia Britannica, www.britannica.com/science/hydrogen.
Energy Education. "Heavy Water." Energy Education, energyeducation.ca/encyclopedia/Heavy_water.t
Wikipedia. "Heavy Water." Wikipedia, the Free Encyclopedia, Wikimedia Foundation, Inc, 14 Dec. 2001, en.wikipedia.org/wiki/Heavy_water. Accessed 9 Feb. 2021.
---. "Isotopes of Hydrogen." Wikipedia, the Free Encyclopedia, Wikimedia Foundation, Inc, 13 June 2005, en.wikipedia.org/wiki/Isotopes_of_hydrogen. Accessed 9 Feb. 2021.
---. "Semiheavy Water." Wikipedia, the Free Encyclopedia, Wikimedia Foundation, Inc, 7 Feb. 2004, en.wikipedia.org/wiki/Semiheavy_water. Accessed 9 Feb. 2021.
---. "Tritiated Water." Wikipedia, the Free Encyclopedia, Wikimedia Foundation, Inc, 4 Feb. 2006, en.wikipedia.org/wiki/Tritiated_water. Accessed 9 Feb. 2021.
---. "Hydrogen." Wikipedia, the Free Encyclopedia, Wikimedia Foundation, Inc, 13 Mar. 2001, en.wikipedia.org/wiki/Hydrogen. Accessed 9 Feb. 2021.
Prior Knowledge