What is van der wall force? who discovered it and in what is it applied? how is it applied?

Van de Waal forces are intermolecular forces (London Dispersion forces, Dipole-Dipole forces, and Hydrogen Bonds). It was discovered by a Dutch scientist called Johannes Diderik van der Waals. Intermolecular forces are the attraction and strength of bonds between molecules, with London Dispersion Forces being the weakest and Hydrogen Bonds being the strongest.

Explanation:

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

he would use the colour black