| − | An Element is a single type of [[atom]], and is defined by its [[periodic number]], or the number of protons present in the [[nucleus]] of the atom. All known elements are grouped together in the [[Periodic table of the elements]]. | + | An Element is a single type of [[atom]], and is defined by its [[Atomic Number]], or the number of protons present in the [[nucleus]] of the atom. All known elements are grouped together in the [[Periodic table of the elements]]. |