Alkali Metal
Alkaline Earth Metal
Transition Metal
Post Transition Metal
Noble Gas
Clear Filters

Periodic Table

The Periodic Table: let’s to learn

Around 1862, a Russian scientist titled Dmitri Mendeleev’s is attributed with exploring the first model of the periodic table. While traveling by train, he began collecting data on the properties of elements and noticed certain patterns. He then rearranged the measured properties to fit those patterns. Doing so allowed him to confidently infer the existence of certain elements. Several other scientists worked to refine the periodic table after the first discovery of noble gases. In 1894, Lord Rayleigh and Sir William Ramsay published a revised version of the table that did not include the open slots for elements they had not yet discovered. However, other chemists objected to this method, arguing that it was not flexible enough to accommodate newly discovered elements. Some investigators openly mocked these concepts. However, one such investigator, George Carey Foster, asked Newlands to re-arrange the elements alphabetically in order to avoid coincidences. The Chemical Society rejected the paper and did not publish it (Scerri, 2019).

Periodic Table - Tablape

Figure 1: The Periodic Table

expand all +
collapse all -
The periodic table is a tabular display/representation of chemical elements. The table has become an icon of chemistry and the sciences. People generally think of it as an icon of chemistry. The table also includes information on the other elements, such as the noble gases and states of matter. The Periodic Table is a key tool in many scientific disciplines (Griffin & Champness, 2020).

1.1. Icon of chemistry

The periodic table, or table of elements, is a framework widely used in the fields of sciences and technology. The different chemical elements are demonstrated in a tabular format. Most people view it as an icon of chemistry, the table can be used for many purposes.

1.2. Mendeleev table

Mendeleev developed the first modern periodic table. He became motivated by the concept of octaves, and he applied it to the process of making predictions about the characteristics of elements. In addition to this, he was able to foretell the characteristics of three elements that hadn’t yet been detected. For example, Gallium was discovered in 1875, and the Mendeleev table predicted its atomic weight and density.

1.3. Rows and columns

The table lists elements by their atomic numbers, and the elements are organized into rows and columns. Each row contains elements that are similar in their properties. For example, the elements in the same column share the same number of electrons and proton mass, which makes them similar to each other.

1.4. Chemical symbol

All the elements in the periodic table have a unique chemical symbol. A few of these symbols are familiar to most people, while others have rich meanings that may be traced back through history. For example, sodium is represented by the Latin word natrium. In addition to the chemical symbol, each element’s box is given a whole number in the left corner of the table, called the atomic number. The electrons are the negatively charged particles surrounding the nucleus.
The periodic table is a chart that illustrates the correlation between element chemical characteristics. It shows how the number of atoms and their relative atomic masses change as we move from left to right. The periodic table also reveals how atoms react to form molecules. The table often shows these properties as color-coded groups (Ruskoski & Boal, 2021).

2.1. Valence electron

The electrons that are located in the least distant shells of an atoms is referred to as the “valence electrons.” It is possible for these electrons to assist in the formation of covalent bonding whenever the outer shells of an atom aren’t really absolutely shut. When 2 atoms form a covalent bond, each of the atoms contributes one of its valence electrons in order for the bond to be formed. The valence electrons then form a shared pair. For example, argon and sodium have atomic numbers of eleven to 18. As the elements progress from left to right, their metallic and non-metallic characteristics increase.

2.2. Element’s shells

The atoms in the element’s shells determine how they react with other elements. In a nutshell, elements are either fully basic or completely acidic. Metals, which make up the first 2 groups of the scientific chart, have the most energetic electrons. The third and fourth groups of the table are non-metals and are inactive.
The periodic table contains 18 groups of elements, and each group has a certain number of valence electrons. For example, group 1 elements only contain one valence electron, while group 18 elements contain eight valence electrons.

3.1. Atomic orbitals

The elements are arranged in rows, from left to right. The first row contains the simplest elements, and the second row has the most elements. The elements in these rows all have the same number of atomic orbitals, with the top row having only one orbital for the electron. The second row adds an orbital, and so on. This continues until all elements have at least seven orbitals.

3.2. 118 atomic elements

The elements that make up matter are laid down in systematic fashion on a chart known as the periodic table. It includes 118 atomic elements that humans have observed. Each element is made up of a positive-charged nucleus that is around by electrons that have a negativity charge. Each element also contains one or more positively charged protons or neutrons, and one or more neutral neutrons.
For today’s researchers and learners, the periodic table is an indispensable instrument. This chart helps them understand how elements behave in a variety of chemical reactions and predicts their characteristics. It consolidates so much of our knowledge of chemistry and is a staple of almost every chemistry lecture or laboratory (Griffin & Champness, 2020).

4.1. Representation of chemistry

In chemistry, a periodic table is a tabular representation of the elements. Few other objects in science are as influential and as visually striking as the periodic table. Although it is widely used in many fields of science, it is most commonly viewed as a representation of chemistry. But the periodic table has numerous additional applications as well.

4.2. Predictions

Periodic table helps us to predict the behavior of a substance and can be used to develop chemical equations. It helps us predict which elements are similar to each other. The periodic table can also help us identify chemical trends, which is critical in solving chemical equations. Members of the same “column” (sometimes called a “group”) tend to have comparable characteristics.

There are three main parts in the periodic table: the metals on the left, the nonmetals on the right and the metalloids in the middle. The elements in each part are color coded to show which belongs to which group. Each part of the periodic table has a particular characteristic. Metals like lithium and potassium reside in one column, while non-metallic reactive elements reside in a different column (Ruskoski & Boal, 2021).

Periodic Table - Metals non metals metalloids

Figure 2:

Parts of the periodic table

We use metals in many of our daily objects and structures. Their rigidity and durability make them a valuable component of many structures. These are classified as precious metals, and they typically cost a lot of money per unit mass. Metals on the Periodic Table are useful for a variety of purposes, from jewelry to aircraft (Scerri, 2019).

6.1. Alkali metals

Alkali metals in the Periodic Table are metals that have low melting and boiling points. It’s also worth noting that their density is rather low. They have excellent thermal and electrical conductivity. The alkali metals have a strong reactivity with both water and air. Sodium, for example, can react with water to form hydrogen gas. As the alkali metals progress down the Periodic Table, they become increasingly reactive. For instance, when exposed to air, francium and cesium will spontaneously ignite. They also react with other elements in group seventeen to form stable ionic compounds.

6.2. Alkaline earth metals

Alkaline earth metals are silvery-white in color and are highly reactive. They lose their valence electrons and form double positive charge ion.  When a chemical reaction occurs, the double-charged positive ion has the edge over a single-charged ion. This property allows alkaline earth metals to react with both oxygen and water to form oxides and hydroxides. These reactions are known as transmetalation reactions, and they are responsible for the formation of various compounds.

6.3. Transition metals

Transition metals are elements with low atomic number and high electron density. This allows them to shed d electrons without suffering a severe hit to their energy levels. One example is manganese, which has two 4s and five 3d electrons. It can either share all of its electrons with another atom or lose all of its electrons altogether, leading to a 7+ oxidation state. Other examples of transition metal compounds are osmium and ruthenium, which are isolated in 8+ oxidation states. Later transition metals require higher energy to remove electrons.

6.4. Post transitional metals

The post-transitional elements in the Periodic Table are elements that are in between transition metals and metalloids. These elements include those from groups 13 and fifteen. They are also considered poor metals. Elements 113 through 116 on the Periodic Table are also part of the post-transition metal family, although their properties are unknown.

6.5. Metalloids

Metalloids are elements that contain three to six valence electrons. These electrons determine the chemical behavior and reactivity of the element. Boron, for example, has three valence electrons, and therefore behaves like a metal during chemical reactions.

6.6. Lanthanides

Lanthanides are found naturally in many minerals. The most common one is monazite, a dark, heavy sand found in the Americas, Australia and South Africa. Monazite contains 50 percent of lanthanide by weight. The process for separating lanthanides from one another is complex and expensive. Lanthanides are very reactive. As a result of their reaction with oxygen in air, hydrogen gas is produced. Because of this, they tend to form ionic compounds.

6.7. Actinides

In chemistry, actinides are classified as rarest class substances. The name actinide is derived from the element actinium, which was discovered in 1940. These elements generate radioactivity rays, as their term indicates. They are also paramagnetic, meaning that their electrons do not retain their magnetism even after they are removed from a magnetic field. These elements have unique characteristics compared to those of the rest of the periodic table.

Chemical inertness characteristics the elements known as “non-metals”. The electronegativity of non-metals is high, meaning that they gain electrons when reacting with another element. They are also not reflective, which makes them unattractive. Moreover, non-metals are brittle and weak. The chemical reactions that occur with them are characterized by covalent and acidic reactions (Griffin & Champness, 2020).

7.1. Halogens

Halogens are a group of elements that contain a variety of properties, including the ability to combine with other elements. Since chlorinated and fluorine typically have just six electrons in their outermost shells, they are not very reactive. They also have a tendency to accept additional electrons, making them strong oxidizers.

7.2. Noble gases

The noble gases are first detected in the Sun. Their characteristic spectral lines led to their discovery. They are mainly found in air. Noble gases are non-reactive elements with low valence electrons. As a result, their atoms tend not to combine with other elements. Noble gases are also referred to as rare gases and inert gases.
There are three possible states for any element: solids, liquids, or gaseous. It can change between these states when subjected to certain temperatures and pressures. In extreme conditions, it can transform into plasma. This state is the most common form of matter in the universe. The states an element are based on their electronic, chemical, and physical properties (Ruskoski & Boal, 2021).

8.1. Gases

Gases are substances with two or more atoms. These substances usually have polar or covalent bonds. Gases are usually the lightest members of a series. They have substantially greater melting capacities than non-polar materials. The gaseous elements form the last vertical column of the Periodic Table. They are the most electronegative.

8.2. Liquids

At a temperature of 2183K, the highest proportion of elements are liquid. These elements have low melting points and high boiling points. The maximum number of elements that are liquids at this temperature is 49. The chemical properties of liquids are caused by Van Der Waal’s forces, which are weaker than ionic and covalent bonds. This means that liquids are more prone to flow. However, liquids are still susceptible to intermolecular attraction, which means they stay close to each other.

8.3. Solids

In the Periodic Table, the term solid describes any substance with a mass that is not empty. It is characterized by its hardness, transparency, refractoriness, and thermal conductivity. The solids in the Periodic Table can be further classified according to their atomic structure. They can be either crystalline or amorphous. Indeed, crystallographic solids are made up of atoms that are very close to one another. Each of these atoms has an identical pattern, and these patterns are repeating.

8.4. Unknowns

The Periodic table contains the known elements and their atomic number, but scientists are still trying to figure out which ones are new. Some are speculative while others are purely theoretical. Those elements that are not known are called Unknowns of the Periodic table. Some are the heaviest elements and are unknown to science. These unknowns include transactinides and tennessine (Ts). Similarly, there are some unknowns about the elements. For instance, the percentage abundances of some elements are not known, and their atomic weights have not been determined yet.
As in periodic table, the elements are arranged into columns going to represent “Groups.” The table is divided into 18 Groups. In periodic table, groups are a common tool in learning about the properties of chemicals. The first group contains elements with one valence electrons, while the last group has eight valence electrons. Mendeleev’s original periodic table consisted of seventeen groups, each containing seven elements. Groups in the Periodic Table can be categorized by their reactivity, which refers to the relative ease with which they can form a compound. It’s also possible for them to share characteristics, including an identical amount of electrons in respective outermost shells (Scerri, 2019).
Horizontal row of elements from left to right is called period. Each period in the Periodic Table is numbered from one to seven. Each period contains an element with a different number of electrons. The elements within each period have different chemical properties (Griffin & Champness, 2020). For example, sodium and magnesium are both metals, but sodium loses one electron during chemical reactions, while magnesium loses two electrons. In contrast, chlorine tends to gain an electron during reactions (Ruskoski & Boal, 2021).


The periodic table/chart contain a framework that integrates the various elements responsible for the composition of all matter. It includes 118 atomic elements that humans have observed. Each element also contains one or more positively charged protons or neutrons, and one or more neutral neutrons. The Periodic Table is a powerful icon of science, encapsulating much of our understanding of chemistry. Although it is widely used in many fields of science, it is most commonly viewed as a representation of chemistry. Despite its long history, the periodic table is still in constant development. Even the heaviest elements still require chemical characterization in order to ensure their properties match their periodic table positions. There are even still some unresolved regions in the periodic table, where a new discovery may be made.


Scerri, E. (2019). The periodic table: its story and its significance. Oxford University Press.
Griffin, S. L., & Champness, N. R. (2020). A periodic table of metal-organic frameworks. Coordination Chemistry Reviews, 414, 213295.
Ruskoski, T. B., & Boal, A. K. (2021). The periodic table of ribonucleotide reductases. Journal of Biological Chemistry, 297(4).