What is a negatively charged atom?
A negatively charged atom (or anion) is an atom that has more electrons than protons. Normal atoms have the equal numbers of each, and thus no electric charge. Some atoms tend to pick up extra electrons because an atom with eight electrons in its outermost electron layer is more stable than one with fewer electrons. These extra electrons usually come from those atoms that only have one or two electrons in the outermost layer (by giving up electrons, such atoms lose their outer layers entirely, leaving a stable eight-electron layer as the outermost).
