The halogens are the elements in group VIIA of the periodic table. These elements only need one additional electron to complete their outer shells. As a result, they form bonds very easily. The halogens with lower atomic numbers are diatomic gases at room temperature, while those with higher atomic numbers are liquids and solids. Finally, the noble gases are the last column on the right of the periodic table. These elements do not readily form compounds and are gases at room temperature.
