In an optical microscope, which electromagnetic waves are used? Which type of waves are used in an electron microscope?

(N/A) $(1)$ To measure very small distances (like the size of a molecule, $10^{-8} \,m$ to $10^{-10} \,m$), instruments like vernier callipers or screw gauges cannot be used.
Optical microscopes use visible light. The wavelength of visible light is of the order of $4000 \; \mathring{A}$ to $7000 \; \mathring{A}$ (where $1 \; \mathring{A} = 10^{-10} \,m$).
Light exhibits wave nature. Therefore, to resolve lengths comparable to the wavelength of visible light, an optical microscope can be used.
However, it cannot be used to resolve dimensions smaller than approximately $10^{-7} \,m$ to $10^{-8} \,m$.
$(2)$ Electron microscopes use matter waves (de Broglie waves) associated with electrons. The wavelength of an electron is typically much less than $1 \; \mathring{A}$, allowing for much higher resolution.