Andreas von Antropoff his Periodic Table in the article ""Eine neue Form des periodischen Systems der Elemente"" in the "Zeitschrift für angewandte Chemie" in 1926. The periodic table is regularly numbered from 1 - Hydrogen to 118 - Oganesson, with "each number representing the number of protons stored within an atom's nucleus in a satisfying balance" compared to most other contemporary tables. In addition he placed the theoretical "Element zero", which had "been a matter of conjecture for nearly a century" atop his periodic table and called it Neutronium. His periodic table was in widespread use in German schools until 1945 and soon
Period (periodic table) across periods. Seven periods of elements occur naturally on Earth. For period 8, which includes elements which may be synthesized after 2016, see the extended periodic table. A group in chemistry means a family of objects with similarities like different families. There are 7 periods, going horizontally across the periodic table. The first period contains the least elements than any other, with only two, hydrogen and helium. They therefore do not follow the octet rule. Chemically, helium behaves like a noble gas, and thus is taken to be part of the group 18 elements. However, in terms of its nuclear