To determine the number of pairs of electrons shared between the two carbon atoms in the chemical compound [tex]\( C_2H_2 \)[/tex], we need to analyze the bonding structure of this molecule.
1. Identify the Compound: The molecule given is [tex]\( C_2H_2 \)[/tex], which is known as acetylene or ethyne.
2. Determine the Bonding:
- Each carbon atom in acetylene needs to form four bonds to satisfy the octet rule (having a total of eight electrons in their valence shell).
- Hydrogen atoms are monovalent, meaning each hydrogen atom forms only one bond.
3. Understand Carbon-Carbon Bonding:
- In acetylene, each carbon atom forms a triple bond with the other carbon atom. This means that three pairs of electrons are shared between the two carbon atoms.
- Additionally, each carbon atom forms a single bond with a hydrogen atom, using one pair of electrons for each bond with hydrogen.
4. Conclusion:
- The triple bond between the two carbon atoms consists of three shared pairs of electrons.
Therefore, the number of pairs of electrons shared between the two carbon atoms in [tex]\( C_2H_2 \)[/tex] is:
[tex]\[ \boxed{3} \][/tex]
Thus, the correct answer is:
C. three pairs of electrons
