Metal introduction

Update:08 Sep 2018
Summary:

  Since the electrons of the metal tend to detach, […]

 

Since the electrons of the metal tend to detach, they have good electrical conductivity, and the metal element usually has a positive valence in the compound, but when the temperature is higher, the resistance will become larger because of the thermal shock of the nucleus. The connection between the metal molecules is a metal bond, so that the connection can be re-established at random replacement positions, which is also a reason for the good metal stretchability.

In nature, most metals exist in a combined state, and a few metals such as gold, silver, platinum, and rhodium exist in a free state. Metallic minerals are mostly oxides and sulfides, and other forms are chlorides, sulfates, carbonates and silicates.

Metal-related substances are gold, silver, copper, iron, manganese, zinc, and the like. At atmospheric pressure and at a normal temperature of 25 degrees Celsius, all metals except mercury (liquid) are solid. Most of the pure metals are silver (grey), only a few are not, such as gold is yellow red, copper is purple.

A substance having a positive temperature resistivity is generally defined as a metal. In the periodic table of the elements containing 112 elements, there are 90 kinds of metal elements. Located at the lower left of the "Bron-Boundary Line", there are metal elements in the s zone, p zone, d zone, and f zone, and all the transition elements are metal elements.

Within the solid metal conductor, there are many free electrons that can move. Although these electrons are not bound to any particular atom, they are bound to the crystal lattice of the metal; even in the absence of an external electric field, these electrons still move randomly due to thermal energy. However, within the conductor, the average net current is zero. Select any cross-section inside the wire. The number of electrons moving from one side of the cross-section to the other at any time interval is equal to the number of cross-sections moved in the opposite direction.