Changes

: The [[electron]]s and their [[Electron Orbital|shells]] are responsible for the chemistry of an [[atom]].

: When [[atom]]s [[bond]] to form [[molecule]]s some [[atom]]s can share their [[electron]]s forming a [[Covalent Bond]], some transfer an [[electron]] from one [[atom]] to another forming an [[Ionic Bond]] while others allow [[electron]]s to pass freely between many [[atom]]s forming a [[Metallic Bond]].