- The halogens are a group of chemical elements that includes fluorine, chlorine, bromine, iodine, and astatine.
- A hydrogen bond is a dipole dipole interaction that occurs between any molecule with a bond between a hydrogen atom and any of oxygen / fluorine / nitrogen.
- The elements hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine and iodine consist of diatomic molecules.
- Potassium also reacts readily with all acids and with many nonmetals, such as sulfur, fluorine, chlorine, phosphorus, and nitrogen.
- As its position in the periodic table would suggest, it is less active than the three halogens above - fluorine, chlorine, and bromine.