Elementary charge the difference between the particle "electron" and the unit of charge "electron" was still blurred. Later, the name "electron" was assigned to the particle and the unit of charge "e" lost its name. However, the unit of energy electronvolt reminds us that the elementary charge was once called "electron". The maximum capacity of each pixel in a charge-coupled device image sensor, known as the "well depth", is typically given in units of electrons, commonly around 10 per pixel. In high-energy physics (HEP) Lorentz–Heaviside units are used, and the charge unit is a dependent one, formula_1, so that = 0.30282212088 .
Surface charge Surface charge Surface charge is the electrical potential difference between the inner and outer surface of the dispersed phase in a colloid. There are many different processes which can lead to a surface being charged, including adsorption of ions, protonation/deprotonation, and the application of an external electric field. Surface charge causes a particle to emit an electric field, which causes particle repulsion and attraction, affecting many colloidal properties. Surface charge practically always appears on the particle surface when it is placed into a fluid. Most fluids contain ions, positive (cations) and negative (anions). These ions interact with the object surface.