The Law of Octaves is about the patterns of elements in the Periodic Table, stating that when elements are aligned according to their atomic weight, every eighth element shares similar properties. For example, hydrogen, fluorine, chlorine, bromine and iodine are all on the same interval.
Dictionary.com points out that in the Law of Octaves, an interval of seven elements separate two with similar properties. For instance, the first line of elements, hydrogen, fluorine, chlorine, bromine and iodine, are all halogens. Halogens cannot be found in nature with just a single atom. A hydrogen molecule always has two hydrogen atoms attached together. Also, fluorine, chlorine, bromine and iodine are all in the form of salt. They are either highly toxic or volatile. Another group of similar elements is the noble gases, which include helium, neon, argon, krypton, xenon and radon. They are gaseous in their natural state and have low boiling temperatures.
The Law of Octaves was first founded by John Newlands, a chemist, in 1865. Although Newlands was the first person to group elements according to patterns, another chemist improved on the fledgling Periodic Table by leaving room for undiscovered elements, ushering in the modern Periodic Table. Later, Newlands was credited with discovering the Periodic Law.