Diatomic Elements (List of 7 Homonuclear Molecules)

We always get confused while learning about the diatomic elements. So here on this blog, we will provide you with everything about the di-atomic elements. There are 7 di-atomic elements in the periodic table: hydrogen, nitrogen, oxygen, fluorine, chlorine, Bromine, and iodine. However, you can find them easily on the periodic table as they comprise the halogen family plus nitrogen and oxygen. These molecules contain two atoms that are bonded together and are non-metals.

The other elements that can form di-atomic molecules are unstable and break easily. Moreover, halogens are a particular type of non-metal, as Bromine is a liquid and all the other elements are gases under normal conditions. And when the temperature is low or the pressure increases, the elements become di-atomic liquids.

What are the Diatomic Elements

The seven molecules that merge two atoms are known as pure di-atomic elements, and all have their molecular formula. They always contain two elements: Hydrogen (H2) and Oxygen (O2), known as homonuclear. That’s why we call them “Di” atomic elements. These are the most stable diatomic molecules at standard temperature and pressure and the building blocks of the entire universe. They are the most durable as they complete the Octet rule. That’s why they are also known as diatomic molecules.

All the elements in di-atomic are non-metallic. The five elements are hydrogen, nitrogen, oxygen, chlorine, and fluorine, which are gases at standard temperature, while Bromine is liquid. Other elements can also form the di-atomic molecule. For example, sodium + chlorine = NaCl (Sodium chloride). That’s how we get the salt, and these types of diatomic molecules are heteronuclear. The bond between the diatomic molecule is non-polar. The other elements can also form di-atomic molecules, but they are weak and can not stay di-atomic for a long time. However, the elements oxygen and nitrogen make up 99% of the Earth’s atmosphere.

List of Diatomic elements & their Nature

The elements consist of two atoms and form a homonuclear molecule. So there are 7 pure di-atomic elements in which 5 molecules are the gases. Moreover, Bromine and iodine are in liquid form and are diatomic gases at a higher temperature. Here is the list of elements.

elements that form diatomic molecules include
elements that form diatomic molecules include
  • Hydrogen- H2
  • Nitrogen-N2
  • Oxygen-O2
  • Fluorine-Fl2
  • Chlorine-Cl2
  • Bromine- Br2
  • Iodine- I2

A well-known chemist, John Dalton’s hypothesis, implies that all elements are monatomic, and the atoms in compounds have the simplest ratios concerning each other. As a single bond joins hydrogen atoms in molecules, halogen atoms like fl2, Cl2, Br2, and I2), which are also bound by a single bond. The double bond joins oxygen, while the triple bond combines nitrogen. As we all know, some of the common elements, like hydrogen, nitrogen, and oxygen, arise as diatomic molecules. These elements played an essential role in exposing the concepts of atoms, elements, and molecules in the 19th century.

Low-temperature formation of diatomic elements

Nitrogen, oxygen, and other di-atomic elements are gases at the standard temperature. They turn into liquid at low temperatures as their forces become weak. They attract by the other neighboring molecules that force them to turn into the liquid state.


  1. How do the Diatomic Elements form?

There are 7 di-atomic elements: Hydrogen, oxygen, nitrogen, Flourine, Chlorine, Bromine, and Iodine. These elements are pure and rare elements consisting of two atoms bonded together. However, a covalent bond shares the atoms by sharing electrons.

  1. Are iodine and Bromine are also Diatomic molecules?

Yes, they both are the diatomic molecules that belong to the halogen family. But Bromine and Iodine are in liquid form while all other diatomic molecules are present in gaseous form.


So, in this blog, we have covered several things about diatomic elements as we all know that oxygen and nitrogen play an essential part in the universe’s basic structure. And they both are present in Di-atomic elements. All other are gases, while Bromine and iodine are in liquid states.