What is the binding force between molecules of a substance if the gas is under ordinary conditions of temperature and pressure?
A.Van der Waals forces.
B.Gravitational forces
C.Buoyant Force
D.None of these

Hint: Van der Waals forces are a broad term for the attraction of intermolecular forces between molecules. Van der Waals forces are classified into two types: weak London Dispersion Forces and stronger dipole-dipole forces.

Complete answer:
Van der Waals forces are the binding forces between molecules in a gas under normal temperature and pressure circumstances. It is also known as the London forces or the dispersion force. It is proportionate to the area of the surface.
As a result, A is the correct answer.
The Van der Waals force, named after Dutch physicist Johannes Diderik, van der Waals, is a distance-dependent interaction between atoms or molecules in molecular physics. These attractions, unlike ionic or covalent connections, are not the product of a chemical electronic interaction; they are consequently comparatively weak and more sensitive to perturbation. At greater distances between interacting molecules, the Van der Waals force quickly diminishes.
 What is Buoyant Force ?
We frequently notice that our bodies feel lighter after swimming in a pool. In addition, when pulling water from a well, the bucket feels lighter until it is half or completely immersed in water. Have you ever pondered why you feel a weight change? When immersed in water or any other fluid, the body experiences a downward force contrary to the direction of the gravitational pull, which is responsible for weight loss. It could explain why a ball of plastic floats in water rather than sinking to the bottom due to its weight.

Note:
Supramolecular chemistry, structural biology, polymer science, nanotechnology, surface science, and condensed matter physics all rely on Van der Waals force. It also underpins many of the features of organic compounds and molecular solids, such as their solubility in polar and non-polar environments.