Question

Why can't you see individual atoms with special tools?

Answer 1

Answer:

Atoms are so much smaller than the wavelength of visible light that the two don't really interact.

Explanation:

To put it another way, atoms are invisible to light itself.

Answer 2

Answer:

Since an atom is so much smaller than the wavelength of visible light, it's much too small to change the way light is reflected, so observing an atom with an optical microscope will not work.