Electron Arrangment

• In order for atoms to be stable they must have a full outer shell
• To get a full outer shell atoms can react with another atom.
• The first shell has a maximum of two electrons, and the rest after that have a maximum of 8.
• If an atom had 1 electron in its outer shell, then if it were to bond with another single atom, then that atom would need 7 electrons in its outer shell to be stable.
• Noble gasses have full outer shells so are unreactive and stable.
• To state the electron structure you can represent it like this-

  Electronic structure of Argon: 2,8,8
• When an atom loses or gains electrons to become stable it becomes and ion and develops a charge. When they lose electrons they gain a positive charge and when they gain electrons they have a negative charge.
• Ions are drawn like this: