Which is the most metallic metal

The importance of the periodic table

The development of the Periodic Table of the Elements (PSE) represents an important milestone in the history of chemistry and had an extremely positive effect on the progress of this science. The properties of elements could now be predicted and explained based on their position in the PSE.

The value

In the PSE, the number of the main group provides information about the maximum value of the elements that are in this main group. All elements of the 5th main group thus achieve the maximum value V. In addition to these maximum values, there are also lower values ​​for the elements from the 4th to the 7th main group.

Main group elements achieve the highest values ​​in their connections with oxygen. This is not the case in the hydrogen compounds. The valence towards hydrogen falls from the 4th to 7th main group from IV to I. The elements oxygen and fluorine are excluded from these rules. Oxygen is always bivalent, fluorine is always monovalent.

The transition elements usually appear in their connections in very different valences. The highest value corresponds to the group number.

Metals and non-metals

All elements can be divided into metals and non-metals according to their properties. Metals tend to give up electrons, non-metals tend to take up electrons. All transition elements are metals (25.3, chapter 25). The main group elements show that all elements of the 1st main group are metals (hydrogen is not counted in the 1st main group) and all elements of the 7th main group are non-metals. In the middle main groups there are metals at the bottom and non-metals at the top.

The following applies in general:

  1. In the main groups, the metallic character increases with increasing atomic number (in the PSE from top to bottom), and the non-metallic character decreases accordingly. With increasing atomic number, i. H. With increasing atomic radius, the attraction of the atomic nucleus on the electrons of the outer shell decreases, so that these can be released more easily. This determines the metal character.
  2. During the periods, the metallic character of the main groups decreases from left to right, and the non-metallic character increases accordingly from left to right. Within a period, the atomic radius decreases from left to right, so that electron acceptance is made easier. This increases the non-metal character.

In the PSE of the main group elements, a diagonal from top left to bottom right can be used to draw a border between metals and non-metals. Elements with metallic and non-metallic properties can be found along this line.