Ionic bond is defined as the electrostatic force of attraction holding the oppositely charged ions. Ionic compounds are mostly crystalline solid having high melting and boiling points, electrical conductivity in moleten state, solubility in water etc. Covalent bond is defined as the force which binds atoms of same or different elements by mutual sharing of electrons in a covalent bond. Covalent compounds are solids, liquids or gases. They have low melting and boiling points compounds. They are more soluble in non-polar solvents.
The valence electrons are involved in formation of covalent bonds is /are called :

Options

A. non-bonding electrons
B. lone pairs
C. unshared pairs
D. none of these

Answer

To determine what the valence electrons involved in the formation of covalent bonds are called, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Covalent Bonds**:
- A covalent bond is formed when two atoms share electrons. This mutual sharing allows each atom to achieve a more stable electron configuration.

2. **Identifying Valence Electrons**:
- Valence electrons are the outermost electrons of an atom that are involved in forming bonds. For example, in a water molecule (H₂O), oxygen has six valence electrons, while each hydrogen atom has one valence electron.

3. **Formation of Covalent Bonds**:
- In the case of water, the oxygen atom shares its electrons with the hydrogen atoms. Each hydrogen shares its single electron with oxygen, leading to the formation of two covalent bonds.

4. **Bonded Electrons vs. Non-bonded Electrons**:
- The electrons that are shared between the atoms in a covalent bond are known as **bonded electrons**. These are the electrons that participate directly in bond formation.
- Electrons that are not involved in bonding are referred to as **non-bonding electrons** or **lone pairs**.

5. **Conclusion**:
- Therefore, the valence electrons that are involved in the formation of covalent bonds are called **bonded electrons**.

### Final Answer:
The valence electrons involved in the formation of covalent bonds are called **bonded electrons**.