Types of chemical bonds

The chemical bonds are responsible for interactions that attract atoms and molecules confer stability to chemicals. There are three types of chemical bonds that we will detail below: Metallic Bond, Ionic Bond and Covalent Bond.

Types of Chemical Bonds

A chemical bond is the force that binds atoms together  to form chemical compounds . This union confers stability to the resulting compound. The energy required to break a chemical bond is called the bond energy. There are three types of bond between atoms:

• Metallic Bond: It occurs only between metallic atoms of the same element that constitute solid structures, it is a strong bond, which joins the atomic nuclei together surrounded by their electrons like a cloud.
• Ionic Bond:  It consists of the union or electrostatic attraction between particles with electrical charges of opposite signs called ions.
• Covalent Bond : nonpolar, polar, simple, double, triple, dative. It occurs between non-metallic atoms and similar electromagnetic charges that join and share some pairs of electrons from their valence shell.

Thanks to these links, all the compounds that exist in nature are formed.

It is a fact that the atoms that make up matter tend to unite through various methods that balance or share their natural electrical charges to achieve more stable conditions than when they are separated. Chemical bonds constitute the formation of organic and inorganic molecules , and therefore are part of the basis of the existence of living organisms , in a similar way chemical bonds can be broken under certain and certain conditions.

This can occur by subjecting chemical compounds to high temperatures, applying electricity or promoting chemical reactions with other compounds, for example if we apply electricity to water it is possible to separate the chemical bonds between hydrogen and oxygen that make it up, this process is called electrolysis.

1- Metallic Link

The metal links are, as the name implies, a type of chemical bonding that occurs only between the atoms of the same metallic element , thanks to these types of linkages metals achieve very compact and resistant molecular structures.

Here what happens with the valence electrons is that they leave their orbits around the atomic nucleus when it joins another, and they remain around both nuclei as a kind of electronic cloud. In this way, the positive and negative charges maintain their attraction, firmly holding the atomic assembly and reaching important margins of hardness, compaction and durability.

Properties of a Metallic Link

For the metal bonds should many of the typical properties of metals, such as its strength, toughness, and even its ductility , good conducting heat and electricity metals in fact due to the particular arrangement of electrons in cloud shape around the nuclei , allowing their mobility throughout the whole. Moreover, the luster of metals is due to this, since this type of bond repels almost all the light energy that hits them, that is, they shine.

The atoms bonded by metallic bonds are usually arranged into hexagonal structures , cubic or specific geometric shape, the exception to the rule is mercury, that despite being a metal, is liquid at room temperature and forms drops.

Examples of Metallic Links

Metallic links are the basis of the world of metals, so any pure metallic element is a perfect example of this, that is, any pure element without mixing with other metals or elements will be kept together by metallic links.

Examples of Metallic Links:

• Links between silver atoms
• Bonds between gold atoms
• Bonds Between Cadmium Atoms
• Bonds between iron atoms
• Bonds Between Nickel Atoms
• Bonds between zinc atoms
• Bonds between copper atoms

2- Ionic Bonds

The ionic bond , consists of the electrostatic attraction between particles with electrical charges of opposite signs called ions, the metal loses electrons and becomes a positive metal ion called cation. These electrons pass to the non-metallic element and it transforms into a negatively charged ion called an anion.

Although the ionic bond is usually distinguished from the covalent one, in reality there is no pure ionic bond , but this model is an exaggeration of the covalent model, there is always some margin of covalence in these bonds .

The cations and anions combine and form a three-dimensional network that is maintained by the forces of electrostatic attraction between ions with different charges, these forces form ionic compounds.

Properties of ionic compounds

• They are strong bonds: the force of this atomic bond can be very strong.
• They are usually solid: at normal temperatures they have a cubic and rigid molecular structure
• They have high melting and boiling points
• Water solubility
• Electrical conduction
• Selectivity: the bonds occur only with some metals in the periodic table.

Examples of ionic bonds

• Fluorides: they are used in the manufacture of toothpastes and other dental supplies
• Sulfates: They are used for additives for construction materials.
• Nitrates: they are used for gunpowder, fertilizers and fertilizers
• Mercury: the compounds of this element are toxic for the human being, therefore it is necessary to handle with caution.

3- Covalent Bonds

A covalent bond is called a type of chemical bond that occurs when two atoms bond to form a molecule, sharing electrons belonging to their valence shell or last energy level, thus reaching the “stable octet”.

Atoms linked by covalent bonds share one or more pairs of electrons from their last energy level, the region of space where the electron density is located in the molecule is called molecular orbital .

This electron density can be defined and calculated using very complex mathematical equations that describe the behavior of electrons in molecules, on the other hand there are also atomic orbitals , which are defined as a region of space that represents the probability of finding an electron around of the atomic nucleus . Thus when several atomic orbitals are combined, molecular orbitals are generated.

Covalent bonds are formed by the behavior of electrons between the atoms that are bonded, it is formed between atoms that do not have a great difference in electronegativity, this bond can be formed between non-metallic atoms or between metallic atoms and hydrogen.

It is important to clarify that there is no absolutely covalent, or an absolutely ionic bond, in fact the ionic bond is often considered as an exaggeration of the covalent bond.

Types of Covalent Bonds

• Simple
• Double
• Triple
• Dative
• Polar Covalent Bonds
• Nonpolar Covalent Bonds

Properties of covalent bonds

• They are soluble in water and insoluble in solvents such as acetone, toluene or gasoline.
• They have low melting and boiling points.
• They are poor conductors of electricity and heat.

Examples of covalent bonds

• Water (HO2) – HOH
• Pure Oxygen (O2) – O = O
• Pure Hydrogen (H2) – HH
• Pure Nitrogen (N2) – N = N
• Acido cianhídrico (HCN)
• Hydrochloric acid (HCl) – H-Cl
• Carbon Dioxide (CO2) – O = C = O