Does Hydrogen have Neutrons? (+ 3 Facts to Know)

Not all hydrogen atoms have neutrons. The most common type of hydrogen atom, called protium, has no neutrons. However, there are two other isotopes of hydrogen, deuterium and tritium, which have one and two neutrons, respectively. 1

Well, this was just a simple answer. But there are few more things to know about this topic which will make your concept super clear.

So let’s dive right into it.

Key Takeaways: Does Hydrogen have Neutrons?

  • Hydrogen has isotopes with varying numbers of neutrons. 
  • Protium has one proton and no neutrons in its nucleus. It is the most common type of hydrogen atom, making up about 99.98% of all hydrogen atoms in the universe.
  • Deuterium has one proton and one neutron in its nucleus. It is a less common type of hydrogen atom, making up about 0.015% of all hydrogen atoms in the universe.
  • Tritium has one proton and two neutrons in its nucleus. It is the least common type of hydrogen atom, making up about 0.00001% of all hydrogen atoms in the universe.

Neutrons in protium

Protium does not have any neutrons in its nucleus. 2 Protium is the most common and simplest form of hydrogen, consisting of just one proton and one electron. Because it has only one proton in its nucleus, it is also known as hydrogen-1 or 1H.

Here are few more details about protium:

  • Protium makes up more than 99% of the naturally occurring hydrogen on Earth. 3
  • Despite not having any neutrons, protium can still undergo certain nuclear reactions, such as fusion with other hydrogen isotopes, or decay into other elements under certain conditions. 4
  • The properties and behavior of protium differ from other isotopes of hydrogen, such as deuterium and tritium, due to the absence of neutrons in its nucleus. For example, protium has a lower boiling and melting point than deuterium and tritium, and it has a different atomic weight and mass than these heavier isotopes. 5 6
  • Additionally, protium does not exhibit the unique chemical properties of deuterium and tritium, which have been used in a variety of applications in chemistry and biology.

Neutrons in deuterium

Deuterium is an isotope of hydrogen that contains one neutron in addition to its proton and electron. 7 It is also sometimes referred to as “heavy hydrogen” due to its greater atomic mass compared to the most common form of hydrogen (protium).

Here are few more details about deuterium:

  • Deuterium is an important isotope in nuclear physics and chemistry, as it can be used in nuclear reactions and as a tracer in chemical reactions.
  • It is also a component of heavy water (D2O), which is used as a coolant and moderator in some nuclear reactors. 8
  • In addition to its scientific applications, deuterium has some industrial and commercial uses as well. For example, it is used in the production of heavy water, as well as in the manufacture of certain types of semiconductors and fiber optic cables. 9
  • Deuterium is relatively rare in nature, accounting for only about 0.0156% of all hydrogen atoms. 10 However, it can be extracted from seawater and other sources using a variety of methods, including electrolysis and distillation.

Neutrons in tritium

Tritium is an isotope of hydrogen that contains two neutrons in addition to its one proton and one electron. 11 This makes it a radioactive and unstable element, as the extra neutrons can cause it to undergo radioactive decay.

Here are few more details about tritium:

  • Tritium can be produced in several ways, including through the interaction of cosmic rays with the Earth’s atmosphere, in nuclear reactors, and through the decay of other radioactive elements.
  • It is often used in nuclear weapons, as well as in fusion reactions as a fuel source. 12 13
  • The presence of tritium can be measured using various techniques, including mass spectrometry and liquid scintillation counting. 14
  • It is also a significant component of low-level radioactive waste and must be handled with care due to its radioactivity. 

Further reading

Is Helium Flammable?
Why Is Helium a Noble Gas?
Is Helium a Metal?
Is Helium Diatomic?
Is Hydrogen a Noble Gas?

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  1. The Isotopes of Hydrogen. (n.d.). The Isotopes of Hydrogen.
  2. Questions and Answers – Is there an atom that does not have neutrons? (n.d.). Questions and Answers – Is There an Atom That Does Not Have Neutrons?
  3. Boudreaux, K. A. (n.d.). The Parts of the Periodic Table. The Parts of the Periodic Table.
  4. Understanding the Outsized Effect of Hydrogen Isotopes. (2021, March 31).
  5. 10.3A: Protium and Deuterium. (2015, June 20). Chemistry LibreTexts.
  6. Tritium | (2018, June 11). Tritium |
  7. What is Deuterium? (2023, January 13). What Is Deuterium? | IAEA.
  8. Heavy water (D2O). (n.d.). NRC Web.
  9. Deuterium oxide – American Chemical Society. (2018, October 15). American Chemical Society.
  10. Krishnamurthy, R. V. (n.d.). Hydrogen isotopes. Encyclopedia of Earth Science, 326–330.
  11. Radionuclide Basics: Tritium | US EPA. (2015, April 15). US EPA.
  14. Benson, R. H., & Maute, R. L. (1962, August 1). Liquid Scintillation Counting of Tritium. Improvements in Sensitivity by Efficient Light Collection. Analytical Chemistry, 34(9), 1122–1124.

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