The key difference between protium and deuterium is that protium has no neutrons in its atomic nucleus, whereas deuterium has one neutron.
Protium and deuterium are isotopes of hydrogen. Therefore, they differ from each other according to the number of neutrons present in their atomic nuclei. Hydrogen contains one proton in the atomic nucleus: thus, the atomic number of hydrogen is 1. There are three isotopes of hydrogen. All three isotopes also contain one proton. We can denote the three isotopes as 1H, 2H and 3H. The values in superscript are the atomic masses of these elements.
CONTENTS
1. Overview and Key Difference
2. What is Protium
3. What is Deuterium
4. Side by Side Comparison – Protium vs Deuterium in Tabular Form
5. Summary
What is Protium?
Protium is an isotope of hydrogen that contains one proton and one electron. It does not have any neutrons in the atomic nucleus. Therefore, there is only a single proton in the nucleus. This isotope is named as such because of the presence of this single proton. We can denote is as 1H or hydrogen-1, where 1 is the atomic mass of the protium.
Protium is the most common and abundant isotope of hydrogen. The abundance is about 99%. This is considered a stable isotope because the proton in this atom has never been observed to undergo decay. However, according to theories, it undergoes decay with a very large half-life, so that it is not observable.
What is Deuterium?
Deuterium is an isotope of hydrogen having a proton, a neutron and an electron. Unlike protium, this isotope has a proton and a neutron together in the atomic nucleus. Therefore, the atomic mass of this isotope is 2. Then we can name it as hydrogen-2 or 2H. Deuterium is also a stable isotope of hydrogen. However, it is not abundant compared to protium. The abundance varies between 0.0026-0.0184%. Unlike tritium, deuterium is no radioactive. It also does not show toxicity.
Water usually contains hydrogen-1 combined with oxygen atoms. But there can be hydrogen-2 combined with oxygen, which forms water. It is heavy water. The chemical formula for heavy water is D2O where D is deuterium and O is oxygen. Moreover, we can use deuterium and its compounds in chemical experiments. For example, they are useful as non-radioactive labels in experiments such as solvents used in NMR spectroscopy. Moreover, we can use heavy water as a neutron moderator and a coolant for nuclear reactors. Deuterium is also a fuel for nuclear fission that is carried out in commercial scale.
What is the Difference Between Protium and Deuterium?
There are three isotopes of hydrogen: protium, deuterium and tritium. The key difference between protium and deuterium is that protium has no neutrons in its atomic nucleus, whereas deuterium has one neutron. Therefore, the three isotopes differ from each other according to the number of neutrons present in their atomic nuclei. Also, due to this reason, the atomic mass of protium is 1 while the atomic mass of deuterium is 2.
Moreover, we can denote the protium isotope as either hydrogen-1 or 1H and the deuterium isotope as either hydrogen-2 or 2H. The protium is the most abundant hydrogen isotope, and its abundance is about 99%; deuterium is comparatively less abundant (about 0.002%). However, it is also stable as protium.
Below infographic summarizes the difference between protium and deuterium.
Summary – Protium vs Deuterium
There are three isotopes of hydrogen: protium, deuterium and tritium. These three isotopes differ from each other depending on the atomic mass, which is the number of protons and neutrons in the atomic nucleus. The key difference between protium and deuterium is that protium has no neutrons in its atomic nucleus, whereas deuterium has one neutron.
Reference:
1. Helmenstine, Anne Marie. “Is Deuterium Radioactive?” ThoughtCo, May. 20, 2019, Available here.
Image Courtesy:
1. “Hydrogen” By Mets501 – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “H-2 atom” By ZYjacklin – Own work (CC0) via Commons Wikimedia