See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

## Solution **Chirality arises from the tetrahedral nature of carbon.** **Step-by-step explanation:** 1. **Tetrahedral geometry requirement**: Carbon forms four single bonds arranged tetrahedrally around it (sp³ hybridization), with bond angles of ~109.5°. 2. **Four different substituents**: When a carbon atom is bonded to four *different* groups, these groups occupy the four vertices of a tetrahedron and cannot be superimposed on their mirror image. 3. **Stereoisomerism**: This asymmetric arrangement creates two non-superimposable mirror-image forms (enantiomers), making the compound chiral. 4. **Why other options fail**: - **(2) Monovalent**: Carbon is tetravalent, not monovalent - **(3) Divalent**: Divalent carbon (like in carbenes) is extremely rare and unstable - **(4) Trivalent**: Trivalent carbon also doesn't represent the normal bonding state **Conclusion**: The tetrahedral arrangement of four bonds around carbon allows for the existence of chiral centers when four different groups are attached, creating optical isomerism. **Answer: (1)**