How do microscopic things vary in size?

Yes, There are many types of microbes which cannot be visible through the naked eye In these situations, Microscope is used.

Explanation:

Light microscopes let us look at objects as long as a millimetre (10-3 m) and as small as 0.2 micrometres (0.2 thousands of a millimetre or 2 x 10-7 m), whereas the most powerful electron microscopes allow us to see objects as small as an atom (about one ten-millionth of a millimetre or 1 angstrom or 10-10 m)

vanderwaal's forces of attraction are the electrostatic intermolecular forces that exist in a molecule due to the temporary or permanent dipoles that are developed in a molecule. in , the major intermolecular forces are dipole-dipole interactions as the molecule is polar (bent structure). so the vanderwaal's forces of interaction in between molecules are the permanent dipole-dipole interactions that develop due to the dipole that exists in between the polar h - s bond. the positively charged hydrogen atom is attracted towards the negative end of the dipole that is sulfur of the adjacent molecule. therefore, these forces of attraction are relatively stronger than that of london dispersion forces that exist in non polar molecules.