The Kossel and Lewis approach is based on the "Inertness of noble gases." This approach was developed by German physicist Walther Kossel and American chemist Gilbert N. Lewis in the early 20th century. It revolutionized our understanding of chemical bonding and provided a crucial foundation for the field of modern chemistry.

Here is a detailed explanation of the Kossel and Lewis approach:

1. Noble Gases and Their Properties:
- Noble gases are a group of chemical elements that include helium, neon, argon, krypton, xenon, and radon.
- These gases are characterized by their extremely low reactivity and stability.
- Noble gases have full valence electron shells, making them chemically inert and resistant to forming chemical bonds with other elements.

2. Valence Electrons:
- Valence electrons are the outermost electrons in an atom.
- They determine the chemical properties of an element, including its reactivity and ability to form chemical bonds.
- Noble gases have a completely filled valence electron shell, which gives them stability and inertness.

3. Octet Rule:
- The Kossel and Lewis approach is based on the octet rule, which states that atoms tend to gain, lose, or share electrons to achieve a stable electron configuration with eight valence electrons (except for hydrogen and helium, which aim for a duplet configuration with two valence electrons).
- Noble gases have a stable electron configuration with eight valence electrons, which is why they are chemically inert.
- Other elements strive to achieve a noble gas electron configuration to attain stability.

4. Lewis Symbols:
- Lewis symbols, also known as Lewis electron dot symbols or Lewis structures, represent the valence electrons of an atom using dots.
- In a Lewis symbol, each dot represents one valence electron.
- The dots are placed around the atomic symbol, with up to two electrons on each side (top, bottom, left, and right).

5. Chemical Bonding:
- The Kossel and Lewis approach helps explain how atoms bond with each other to achieve a noble gas electron configuration.
- Atoms can gain, lose, or share electrons to complete their valence shells.
- Ionic bonding occurs when atoms transfer electrons, resulting in the formation of ions with opposite charges that attract each other.
- Covalent bonding occurs when atoms share electrons to achieve a stable electron configuration.

In conclusion, the Kossel and Lewis approach is based on the inertness of noble gases. By understanding the stability and electron configuration of noble gases, chemists can explain chemical bonding and the reactivity of other elements. The octet rule and Lewis symbols are essential tools in this approach, providing a framework for understanding the formation of chemical bonds.

Reactivity of elements