Isotopes of Hydrogen

1H (protium), 2H (deuterium), and 3H (tritium) are the three naturally occurring isotopes of hydrogen (tritium). An unstable nuclei (4H to 7H) have been created in the lab, but they do not exist in nature. With a half-life of 12.32 years, tritium is the most stable radioisotope of hydrogen. All heavier isotopes are created artificially and have a half-life of less than a zeptosecond (10-21 sec). The most stable isotope is 5H, whereas the least stable is 7H.

Protium

The most common form of hydrogen isotope is 1H. This isotope’s nucleus is made up of only one proton, with a mass of 1.007825 AMU. Hydrogen is most usually found as the diatomic hydrogen gas including other atoms; monoatomic hydrogen is rare. With a bond dissociation enthalpy of 435.88 kJ/mol at 298 K, the H–H bond is one of nature’s strongest. As a consequence, H2 only dissociates to a minor amount until higher temperatures are reached. The degree of dissociation at 3000K is only 7.85 percent. Hydrogen atoms are extremely reactive, combining with practically every element.

Deuterium

The other stable isotope of hydrogen is 2H that has a natural abundance of ~156.25 parts per million in the oceans and makes up around 0.0156 percent of all hydrogen on the planet. Deuterium’s nucleus, known as a deuteron, contains one proton and one neutron (mass number = 2), whereas a protium’s nucleus contains no neutrons. Deuterium has about twice the mass of protium due to the extra neutron in the nucleus (deuterium has a mass of 2.014102 amu, compared to the mean hydrogen atomic mass of 1.007947 amu). Deuterium gas, abbreviated 2H2 or D2, is found in tiny amounts in nature, but it is most typically found in the cosmos linked to a protium 1H atom, creating hydrogen deuteride.

Deuterium reacts chemically similarly to regular hydrogen (protium). However, there are differences in binding energy and length for heavy hydrogen isotope complexes that are bigger than any other element’s isotopic variances. Deuterium and tritium bonds are slightly stronger than their protium counterparts. These differences are enough to cause major alterations in biological responses. Heavy water (D2O) is formed when deuterium replaces conventional hydrogen in water molecules. D2O is about 10.6 percent denser than normal water.

In eukaryotic animals, heavy water is slightly poisonous, with a 25% substitution of body water causing cell division issues and sterility, and a 50% death caused by cytotoxic syndrome (bone marrow failure and gastrointestinal lining failure). Heavy water consumption is not harmful to people’s health. A 70 kg person might consume 4.8 litres of heavy water without major repercussions, according to estimates.

Tritium

Often known as tritium, it is another form of hydrogen isotope that includes one proton and two neutrons. It has a 12.32-year half-life. Tritium is extremely rare on Earth, where trace amounts are created by the interaction of cosmic rays with the atmosphere.

Heavier, synthetic isotopes of hydrogen

The nucleus of 4H comprises one proton and three neutrons. In the laboratory, it was created by blasting tritium with fast-moving deuterium nuclei. The tritium nuclei collected neutrons from the fast-moving deuterium nucleus in this experiment. By detecting the released protons, the presence of hydrogen-4 was determined. 4.02781 ± 0.00011 amu is its atomic mass. It has a half-life of 1.39 ×10−22 seconds and decays through neutron emission.

Another exceedingly unstable heavy hydrogen isotope is 5H. A proton and four neutrons make up the nucleus. In a laboratory, it was created by blasting tritium with fast-moving tritium nuclei. Two neutrons from one tritium nucleus are captured by the other, resulting in a nucleus with one proton and four neutrons. The remaining proton could be recognised, and hydrogen-5 could be determined. It has a half-life of at least 9.1 × 10−22 seconds and decays by double neutron emission.

6H has a half-life of 2.90×10−22 seconds and decays via triple neutron emission. One proton and five neutrons make up the nucleus.

The neutrons of helium-8 were transferred to the nucleus of hydrogen. The “RIKEN telescope,” a device consisting of numerous layers of sensors positioned beyond the target of the RI Beam cyclotron, detected the two remaining protons.

Conclusion

There are three isotopes of hydrogen in the atmosphere. Hydrogen is a mixture of two forms, an ortho form and a para form, which differ in their electronic and nuclear spins, in addition to being a mixture of three isotopes. At ambient temperature, atmospheric hydrogen is made up of approximately 34% ortho-hydrogen and 14% para-hydrogen. The physical properties of the two types differ slightly.