Question

Give an example of a monatomic molecule.

Answer 1

Hint :The term "monatomic" is a mixture of the terms "mono" and "atomic," which refers to a single atom. Both chemical elements are monatomic gases in the gaseous phase at sufficiently high temperatures.

Complete Step By Step Answer:
Noble gases are monatomic gases because they are non-reactive in nature, which is one of their characteristics.
One example of a monatomic molecule is Argon. The atoms in a monatomic gas are not bound to each other.
The noble gases helium, neon, argon, krypton, xenon, and radon are the monatomic elements under normal temperature and pressure conditions. These are all gaseous elements.
The valence electron shells of monatomic noble gases are filled. To put it another way, they follow the octet theory. Monatomic elements do not readily form chemical bonds or compounds with other elements due to their stability. Except for helium, neon, and oganesson, scientists have synthesized compounds of all of the noble gases.
Since the atoms don't get close enough to form chemical bonds, monatomic oxygen, hydrogen, and other elements remain in the near-vacuum. Since there is too much kinetic energy for bonds to form or the energy breaks chemical bonds between atoms, nearly all elements form monatomic gases at extremely high temperatures or when exposed to enough radiation.

Note :
Since monatomic elements have only translational energy and no rotational or vibrational energy, they behave differently than diatomic and triatomic elements or compounds. This makes it easier to predict their thermodynamic behaviour.