Covalent bond is formed between the atoms of

Options

A. metals
B. non-metals
C. metals and non-metals
D. metals and metalloids.

Explanation

### Step-by-Step Solution:

1. **Definition of Covalent Bond**: A covalent bond is a type of chemical bond that involves the sharing of electron pairs between atoms. This sharing allows each atom to attain the electron configuration of a noble gas, achieving stability.

2. **Atoms Involved in Covalent Bonds**: Covalent bonds are primarily formed between non-metals. Non-metals have higher electronegativities and tend to gain or share electrons rather than lose them.

3. **Example of Covalent Bond Formation**: A classic example of covalent bond formation is the bond between two fluorine (F) atoms in the diatomic molecule F2. Each fluorine atom has 7 electrons in its valence shell and needs one more electron to complete its octet.

4. **Sharing of Electrons**: In the case of F2, each fluorine atom shares one of its valence electrons with the other. This sharing results in a pair of electrons that are counted as belonging to both atoms, thus forming a covalent bond.

5. **Comparison with Ionic Bonds**: In contrast, metals (like sodium) tend to lose electrons to achieve stability, leading to the formation of ionic bonds. For example, sodium (Na) has the electronic configuration of 2-8-1 and will lose one electron to form Na+ ions, which then bond with non-metals to form ionic compounds.

6. **Conclusion**: Therefore, covalent bonds are formed between the atoms of non-metals, as they prefer to share electrons rather than lose them.