Why do most of the elements try to participate in the chemical combinations? i. To gain more electrons ii. To achieve Inert Gas configuration iii. To complete their octet iv. To complete their inner shells Choose the correct option among the following

Why do most of the elements try to participate in the chemical combinations? i. To gain more electrons ii. To achieve Inert Gas configuration iii. To complete their octet iv. To complete their inner shells Choose the correct option among the following Correct Answer Both (ii) & (iii)

The correct answer is option 2.

Key Points

• Chemical combinations are reactions that elements participate in.
• During a chemical combination, there is a formation of a new interaction between the elements participating. This new interaction is called bond formation. 
• The driving force behind these bond formations is the unsaturation of electric forces.
• All elements try to achieve eight electrons in their outermost shell. This is called the octet rule. The octet rule states that all elements try to achieve the nearest noble gas configuration by accepting, losing, or sharing electrons.
• After fulfilling this condition i.e., attaining 8 electrons in its outermost shell, the elements are said to be stable.
• The inert gases have eight electrons in their outermost shell and thus do not participate in chemical reactions.
• Other elements in order to satisfy these conditions of attainment of eight electrons, participate in chemical combinations.
• Sometimes, they take electrons from other elements having an excess of electrons, or sometimes they share.
• For example, in the compound, KCl, there is a chemical bond between potassium and chlorine.
• K in its elemental form has one extra electron and after losing that it can obtain its octet.
• On the other hand, elemental Chlorine has one electron short for octet, so during the chemical combination,  Potassium donates one electron to Chlorine becoming K^+, and Chlorine gains one electron becoming Cl^-.
• In this way, both elements obtain octet and become stable. Now, Chlorine will not try to gain any more electrons, as its octet is satisfied. 
• One other way of gaining an octet is by sharing electrons. A simple example will be the formation of HCl.
• Hydrogen has one electron in its outermost shell and requires only one more electron to achieve the electronic configuration of its nearest noble gas, i.e., Helium.
• So, it shares one electron with Chlorine, in that way Chlorine achieves its octet, and Hydrogen achieves the configuration of Helium.

Important Points

• It is important to note that as chemistry is a science of exceptions, the octet rule is not always satisfied or obeyed.
• Inert gases like Xenon participates in chemical reactions forming bonds.