The metallic bond is a force that is responsible for keeping together the atoms in a substance metal . In most cases, the outermost electron shell of each of the metal atoms overlaps with a large number of surrounding atoms. As a consequence, valence electrons continually move from atom to atom and are not associated with any specific pair of atoms. In other words, the valence electrons in metals, unlike those in covalently bound substances, are not localized, they are able to roamrelatively freely throughout the entire length of the glass. The atoms that leave the electrons are converted into positive ions , and the interaction between such ions and valence electrons gives rise to the cohesive or binding force that holds the metallic crystal together.
The metallic bond is the one that occurs between two atoms of two metals in which all the atoms lose their electrons in their outermost shells which move freely between them creating an electronic cloud .
- Characteristics of the metallic bond
- How the metallic bond is formed
- Structure of the metallic bond
- Examples of metallic bond
Characteristics of the metallic bond
The main characteristics of this type of link are the following:
- They are non-directional , this means that they have electrostatic attraction .
- They have great metallic bond strength which depends on the charge that the cations have.
- They have a metallic luster as a result of the interaction that occurs between the electrons of the metal with the different wavelengths.
- They have electrical power conduction .
- They have conduction of thermal energy when electrons are heated that can then acquire a huge amount of kinetic energy and can move to colder regions.
- They have characteristics of energy dissipation when shock occurs and cation vibration.
How the metallic bond is formed
The metallic bond takes place when the combination of metals occurs with each other. It is known that metals need to give up some of their electrons in order to reach the noble gas configuration, the metals then lose the valence electrons , thus forming a cloud of electrons between their positive nuclei.
Among the main properties of metallic bonds we can mention the following:
- Metallic bonds are usually solid at room temperature, except for mercury .
- The boiling and melting point of the bonds is very varied, this because the bonds are very strong.
- They have the property of having a metallic luster.
- They are not brittle, but they do have great flexibility and are also ductile.
- They have a good conductivity of heat and electricity. This property is due to the fact that electrons have the ability to act freely in their movements.
- They are usually found as solids at room temperature.
- They are quite soluble in the molten state.
Structure of the metallic bond
In metallic bonds, each atom is divided into twelve atoms , six of them are in the same plane, three are located above and three below. The electrons are extracted from their orbitals by low electronegativity that possess. It is a link of strong consistency , which is formed between elements that belong to the same species. Although their structure is very close, their nuclei can interact in electronic clouds , packing in three dimensions, which is why the nuclei are surrounded by these clouds.
There are two different theories regarding the metallic bond which are:
- Theory of the sea of electrons: It is also called the theory of electronic gas and constitutes a simple idea of the bond. It says that the metallic structure is made up of cations made of metal that are submerged in a sea of electrons , and that these valence electrons are those of the atom of a metal and that, in addition, they have the ability to avoid different electrostatic repulsions. that can occur between positively charged ions. Explain the conductivity of metals in the ability of electrons to move. The disadvantage of the theory is that it cannot quantitatively explain conductivities.
- Band theory : This theory is born from the application of quantum mechanics that metallic bonds have. It says that from two atomic orbitals , which correspond to two atoms, we can get to obtain two different molecular orbitals. The greater the number of molecular orbits, the smaller the difference in energy between them.
Examples of metallic bond
Metallic bonds can and are used in activities of daily living . A fairly common example is that of bronze , which is created from an alloy of tin and copper and is used in the construction of bells and statues . The steel , consisting of carbon and iron, is another example. This alloy makes the steel stronger and can be used in the production of cookers and freezers , construction and in the manufacture of bridges .