Complex sentence: For example, a barely-visible (0.1mm) grain of sand contains around 10 17 atoms and 10 18 electrons, where each of these attracts or repels every other by Coulomb's law.
Split into simpler sentences: For example, a barely-visible (0.1mm) grain of sand contains around 10 17 atoms and 10 18 electrons. Each of these attracts or repels every other by Coulomb's law.