How Does Neon Signs Work?

Covalent bond. It occurs when two atoms share their electrons as, for example, when two hydrogen molecules(H + H = H 2 ) or other similar elements are joined, such as nitrogen(N 2 ), oxygen (O 2 ), chlorine(Cl 2) ), etc.

The covalent bond between the two hydrogen atoms (H 2 ).Metallic bond. It is done when the electrons that are rotating in the last orbit of the atoms of metal move through a molecular structure, keeping it together as it happens, for example, with copper: Cu

Diving conductivity band

Driving band

It is called “conduction band” at the energy level, where the attraction of the nucleus of the atom on the electrons is weakest. This level corresponds to the last orbit of the atom, which can thus share its electrons among the rest of the atoms of a body, allowing them to travel through it in the form of an electron cloud. 

When an atom is excited using electrical current, light, heat, etc., some of its electrons can absorb energy, jump into the conduction band and move from one molecule to another within a body.

Each atom has a certain number of electrons revolving around it in different orbits forming an electronic cloud; however, it is only the last orbit that determines the amount of valence or driving properties that each chemical element possesses, in any atom that the final realm admits only a maximum of eight electrons to complete its atomic structure. The tendency of all is to complete it.

An atom with seven electrons in its last orbit (valence -1, for example) tends to attract the electron. It needs to capture it from another atom that possesses only one in its last orbit (valence +1, for example). In turn, the atom that has between one and three electrons in the last orbit tends to yield them to other atoms that require it so that it can complete the eight. 

This mechanism called “rule of the octet” gives rise to the creation of different chemical combinations, the conduction of heat and the conduction of electric current, according to the way in which the atoms are excited.

Conductivity

It is the property of the atoms of metals that allows the electrons that rotate in their last orbit or band of conduction to move through their molecular structure, conducting heat or electricity. 

According to the greater or lesser conductivity that a body has, they are classified into three groups:

• Drivers

• Insulators or dielectrics

• Semiconductors

Drivers. All metals conduct, to a greater or lesser extent, electricity and heat, because their atoms tend to easily give up the electrons that rotate in their last orbit. Gold (Au), silver (Ag), copper (Cu), aluminum (Al), tin (Sn) and platinum (Pt) are good conductors, while iron (Fe) and lead ( Pb), for example, they are to a lesser extent.

Insulators or dielectrics. They are materials in which the electrons that rotate in the last orbit of their molecules are strongly attracted to the nucleus. This prevents them from moving freely through the molecular structure to which they belong, so they do not conduct heat or electricity. Among the good insulating materials are mica, Teflon, porcelain, plastics, etc. Air is also considered a good insulator of heat and electricity. 

Semiconductors. As the name suggests, these materials are not exactly good conductors of electricity, but when they are excited their electrons can pass to the conduction band and facilitate the electronic flow, although always in only one direction. Hence its name of “semiconductors.” 

Among the elements or semiconductor materials most used by the industry to manufacture electronic devices such as diodes, transistors, integrated circuits and microprocessors are silicon (Si), germanium (Ge) and gallium arsenide (GaAs).