How is a pure substance different from a mixture? a. pure substances cannot be seperated by physical means.
b. a pure substance is heterogeneous.
c. a mixture is made of ine substance.
d. mixtures cannot be seperated by physical means.

Pure substances cannot be separated by physical means.

Explanation:

A pure substance is a substance which contains definite composition of only one type of component. Hence, it cannot be separated by physical means.

On the other hand, a mixture is a substance which contains two or more than two types of components and they can be separated by physical means as well.

Thus, option (a) is correct one that is pure substances cannot be separated by physical means.

intermolecular forces are the forces between molecules or particles.

there are two kinds of van der waals forces: weak london dispersion forces and stronger dipole-dipole forces.

in molecule of water there are dipole-dipole forces between negatively charged oxygen from one molecule of water and positively charger hydrogen of another molecule of water.

hydrogen bond is an electrostatic attraction between two polar groups that occurs when a hydrogen atom (h), covalently bound to a highly electronegative atom such as flourine (f), oxygen (o) and nitrogen (n) atoms.