The Types of Chemical Bonds and Their Effects on Scientific Progress

Stable chemical compounds form due to the types of chemical bonds between at least two atoms. This overview explains each one and how chemists can impact science by learning more about these bonds.

What Is a Chemical Bond? 

A chemical bond is an electrostatic attraction between at least two atoms that creates more stability. The resultant joining forms a molecule, crystal or ion. Additionally, the atoms can stay bonded indefinitely until an external force or energy source severs the link. 

What Are the Main Types of Chemical Bonds?

When people refer to the main types of chemical bonds, they categorize them as primary or secondary. Those in the primary category are covalent, ionic and metallic. Then, secondary bonds are hydrogen or Van der Waals. Let’s look at each in more detail.

Covalent Bonds

Covalent — also known as molecular — bonds form between atoms that share a pair of electrons. These bonds usually occur between non-metallic elements. Another distinctive characteristic of these types of chemical bonds is that the electron density is highest in the center of the bond. Additionally, the electrons are most likely in between atoms than at either end. 

Covalent bonds can either be single or multiple. The former type means the two atoms share only one pair of valence electrons. When more than one valence electron pair is involved, a multiple bond forms. Double and triple bonds are the most common instances of these. Moreover, oxygen, nitrogen and sulfur are some of the elements that frequently create multiple covalent bonds.

Polar and non-polar are two other categories attributed to covalent bonds. Polar covalent bonds show unequal electron sharing, resulting in an distribution that leaves one atom with a partial positive charge and the other with a partial negative charge. Conversely, equal electron sharing occurs in non-polar covalent bonds and results in a balanced distribution of electron sharing. These non-polar covalent bonds only occur between two atoms of the same element.

Ionic Bonds

Ionic bonds happen when the electron transfer occurs between one atom to another. These are typically between metal and non-metallic elements. Additionally, the atom in the bond that is comparatively more able to attract electrons — the most electronegative atom — takes the electrons rather than creating a shared arrangement. 

This change causes the atom that gains electrons to develop a negative charge, while the one that loses them has a positive charge. Ionic bonds are an example of electrons affecting how atoms interact. The more unequal the sharing of electrons is between the involved atoms, the greater the chemical bond’s ionic character. 

Metallic Bonds

As the name suggests, these types of chemical bonds occur between a metal’s atoms. However, they behave much differently from covalent bonds, during which electron sharing is densest in particular areas. Metallic bonds simultaneously occur among all a molecule’s atoms. 

Additionally, metallic bonds result in metals having particular properties, such as electrical and thermal conductivity or strength.

Having covered all the primary types of chemical bonds, let’s look at those categorized as secondary. A key differentiator of all the primary types is that these bonds occur through the transfer or sharing of electrons. However, secondary bonds do not include either. Instead, the attraction happens due to the subtle attraction from the atom’s respective positive or negative charges. The associated force causing the bond is called a directional electrostatic attraction. 

Hydrogen Bonds

One of the atoms in a hydrogen bond is always hydrogen, but the other is an electronegative atom, such as chlorine or oxygen. Additionally, these types of hydrogen bonds are weaker than some others explored above. Consider the example of a covalent bond between hydrogen and oxygen. A hydrogen bond between the same two elements is only about 5% as strong, but it is still resilient enough to tolerate temperature fluctuations. 

Although hydrogen bonds can occur between hydrogen and any other electronegative atom, they happen particularly frequently in water. 

Van Der Waals Bonds

Van Der Waals are the weakest types of chemical bonds between covalent molecules. They typically form in numerous liquids, polymers and gases, ultimately impacting the strength and stiffness of the resulting materials. Additionally, attraction occurs between neutral molecules or atoms.

How Do the Types of Chemical Bonds Impact Scientific Research? 

Most people first learn about chemical bond types in chemistry class. Sometimes, that foundational knowledge forms the building blocks of a career as a chemist or other professional who explores chemical bonds and how they affect modern innovations. 

Breaking the Bonds Between Pervasive Chemicals

People often refer to per- and polyfluoroalkyl substances (PFAS) as “forever chemicals” because of how long they endure in the environment. How might scientists’ knowledge of the types of chemical bonds allow them to tackle these chemicals?

These substances have strong carbon-fluorine chemical bonds, helping make them more pervasive in the world. However, one group discovered a specific bacterial species that can break them. More specifically, those involved said this is the first bacterium used for such an application. 

They also clarified that the bacteria only tackles unsaturated forever chemicals, which have chemical structures featuring double carbon-to-carbon bonds. However, they believe this progress will pave the way for more developments that help people understand the responsible mechanism. Then, they could tweak it to work on more PFAS types. 

Additionally, this discovery could result in more cost-effective ways to treat PFAS pollution in groundwater. That approach destroys the compounds before water reaches wells and spreads throughout populations. Those results could prove crucial since researchers have already linked forever chemicals to health issues. 

Developing Sustainable Chemical Processing Opportunities 

Chemical processing is essential to the production of many plastics, fuels and other products on which the world depends. However, as more decision-makers prioritize making their operations more sustainable, they have begun examining current processes and looking for greener alternatives. Many people working in industrial sectors know innovative changes must occur before sustainability improvements can happen.

One example comes from an engineering team searching for a greener way to handle thermal catalysis. This step uses massive amounts of heat to break chemical bonds, which is necessary for later synthesis. The group relied on a precisely controlled electrocatalytic system that severs butane’s carbon-carbon and carbon-hydrogen bonds. 

Additionally, they orchestrated an approach to dynamically control electrode potentials, which controlled the catalytic reactions and enabled the rearrangement of the electrochemical interface. Besides enabling this chemical processing step without high energy usage and heat, this alternative provides a more selective way to turn hydrocarbons into other chemicals. 

Chemical Bonds Shape Products and Industries

Although most people rarely or never think of chemical bonds, the associated results clearly affect the products many individuals use daily. Similarly, efforts to learn more about working with chemical bonds will spur industrial progress.