Key concepts
An ion has unequal numbers of protons and electrons. Cations are positive; anions are negative. In water, oxygen ends of water molecules point toward cations, while hydrogen ends point toward anions. Mobile ions carry current.
Scientific model
The simulation combines Brownian motion with electric drift. Conductivity is estimated from concentration, charge, diffusion, temperature, and the Nernst–Einstein relationship. Positions and times are visually scaled educational approximations.
Applications and misconceptions
Ions enable nerve impulses, batteries, electrolysis, water treatment, and mineral transport. Ions are not free electrons, and ionic solutions remain electrically neutral overall even while charges move.