U

Ultra-high resolution scanning electron microscope
This equipment uses an electron beam that is finely focused to about 0.1 nanometers (one millionth of a centimeter) to scan the top of the sample in order to directly observe the atoms in the sample based on the intensity of the electron beam transmitted by the sample.

V

Van der Waals force
This is the force that arises between atoms, molecules, and ions as a result of fluctuations in the distribution of electrons around the nucleus.