Anomalous Properties

a brief introduction to lithium

The Alkali Metals are the first group of elements in the periodic table. Lithium is the first element in the first chemical group. So, what causes it to behave in such a different manner? Because of the element’s small size, it exhibits anomalous behavior, which is explained below. Let’s take a look at how.

Relationship in Diagonal Form

It has been observed that the periodic properties of Lithium, Beryllium, Boron, Carbon, Nitrogen, Oxygen, and Fluorine are slightly different from those of the other elements belonging to Groups 1, 2, and 13-17, respectively, compared to the rest of the elements. For example, Lithium and Beryllium combine to form covalent compounds, whereas the rest of the elements in Groups 1 and 2 combine to form ionized compounds. Furthermore, the oxide that is formed by Beryllium when it reacts with oxygen is amphoteric in nature, in contrast to other Group 2 elements that form basic oxides when they react with oxygen. Another example is carbon, which has the ability to form stable multiple bonds, whereas Si=Si double bonds are not very common in the natural world.

As a result, it has been conclusively 

Established that the elements of the second period are distinct. The truth is that they exhibit periodic properties that are similar to the second element of the next group (for example, lithium is similar to Magnesium and Beryllium is similar to Aluminum), or in other words that they have a diagonal relationship with the first element of the next group.

Various explanations for atypical periodic properties

The following are the reasons for differences in periodic properties and, consequently, differences in chemical behavior:

Because of their small size, these atoms

Electronegativity is extremely high.

A high charge-to-radius ratio

These elements also have only four valence orbitals available for bonding (2s and 2p), as opposed to the nine orbitals available to the other members of the respective groups (3s, 3p, and 3d), resulting in a maximum covalency of four for these elements. For this reason, only [BF4]– can be formed by Boron, whereas [AlF6]3– can be formed by Aluminum.

The Element’s Physical Characteristics

In nature, lithium is a highly electropositive element. This is the reason why it can form covalent bonds with other substances. Its ion exhibits polarization behavior that is similar to that of magnesium ions in some respects. The result is that magnesium and lithium have a diagonal relationship with respect to one another. There are a variety of explanations for why they have such a diagonal relationship with one another. Let’s take a look at the various reasons for this.

Conclusion

Alkali metals react violently with oxygen, forming oxides, peroxides, and superoxides that vary in size and composition depending on the metal. With the exception of lithium, all other elements, including alkali metals, form oxides, while the rest of the elements form peroxides and superoxides.