Hydrogen, helium, lithium, beryllium, boron. Carbon, nitrogen, oxygen, fluorine, neon.
Sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, argon, potassium, calcium.
Extended data:
Russian chemist dmitri mendeleev invented the periodic table in 1869. Since then, there have been 170 types of periodic tables, which can be summarized as: short table (represented by Mendeleev), long table (represented by Werner type) and super-long table (represented by Baltar type); Plane spiral table and circular table (represented by Damkoff type); Three-dimensional periodic table (represented by Lacey's cone-column three-dimensional table) and so on.
Some properties of the periodic table of chemical elements;
First of all, the metallic properties of elements:
(1) During the same period, the metallicity of elements decreased from left to right, while the nonmetal increased.
(2) The metallicity of the elements of the same main group increases from top to bottom, while the nonmetal decreases.
Second, the acidity of the highest valence oxide hydrate:
The stronger the metallicity of an element, the stronger the alkalinity of the hydrate of its highest valence oxide; The stronger the nonmetal of elements, the stronger the acidity of the highest valence oxide hydrate. (except f and o).
Third, nonmetallic gases:
The stronger the nonmetallic elements are, the more stable the gaseous hydride is. At the same time, the stronger the nonmetallic nature of nonmetallic elements, the stronger the acidity of gaseous hydride aqueous solution; The stronger the nonmetallic nature of nonmetallic elements in the same main group, the weaker the acidity of gaseous hydride aqueous solution.
Baidu Encyclopedia-Periodic Table of Chemical Elements