Electrons move randomly around the nucleus of an atom and are arranged in energy shells or levels. The first shell can hold a maximum of 2 electrons, while the second and third shells can each hold up to 8 electrons. Electrons fill the first shell before moving to higher shells in an atom.

1. *Electrons:Move randomly around the nucleus of the atomArranged in energy shells or levelsRules for electrons in each shell:First shell has max of 2 electrons2nd and 3rdshell have a max of 8First shell fills up first, then the second, then the third…etc.