In the formation of a moleculae only the outer shell electrons take part in chemical combination and are known as

Options

A. valence electrons
B. inner electrons
C. inert electrons
D. reactive elctrons

Answer

**Step-by-Step Solution:**

1. **Understanding Outer Shell Electrons**: In the context of chemical bonding, only the electrons in the outermost shell of an atom are involved in the formation of molecules. These electrons are crucial because they determine how an atom will interact with others.

2. **Identifying the Term**: The electrons involved in chemical bonding are specifically referred to as "valence electrons." These are the electrons that reside in the outermost shell of an atom and are responsible for the chemical properties of that element.

3. **Example of Hydrogen**: For instance, in a hydrogen molecule (H₂), each hydrogen atom has one electron in its outer shell. When two hydrogen atoms come together, they share their valence electrons to form a covalent bond, resulting in a stable molecule.

4. **Example of Ammonia (NH₃)**: In the case of ammonia, nitrogen has the electron configuration of 1s² 2s² 2p³. The outermost shell (2s and 2p) contains five valence electrons. When nitrogen bonds with three hydrogen atoms, it shares its valence electrons with them, completing both the nitrogen's octet and the hydrogen's duet.

5. **Conclusion**: Therefore, the electrons that participate in the formation of molecules are known as "valence electrons." They are more easily involved in bonding due to their higher energy level and reduced attraction to the nucleus compared to inner shell electrons.

**Final Answer**: In the formation of a molecule, only the outer shell electrons take part in chemical combination and are known as **valence electrons**.

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