Carbon and Its Bonding
NCERT Class 10 • Science • Chapter "Carbon and Its Compounds"
Carbon and Its Bonding
Carbon forms far more compounds than any other element, running into millions. Two properties explain this: carbon's ability to link with itself in long chains and rings, and its ability to form four strong covalent bonds with other atoms.
Why Carbon Is Special
- Catenation is the ability of carbon atoms to bond with one another to form long chains, branched chains and rings.
- Tetravalency means carbon has four valence electrons, so it forms four covalent bonds.
- Carbon shares electrons rather than transferring them, because gaining or losing four electrons would need too much energy.
- Carbon bonds are strong and stable, which makes its compounds durable.
- Carbon also bonds readily with hydrogen, oxygen, nitrogen, sulphur and the halogens, which multiplies the possibilities.
- Isomers are compounds with the same molecular formula but different structures, and carbon forms these easily.
- Because the bonds are covalent, most carbon compounds are poor conductors with low melting and boiling points.
Allotropes of Carbon
- Allotropes are different physical forms of the same element in the same physical state.
- In diamond, each carbon atom is bonded to four others in a rigid three dimensional structure, which makes it the hardest natural substance.
- Diamond is used in cutting and drilling tools and in jewellery, and it does not conduct electricity.
- In graphite, each carbon atom is bonded to three others in layers that slide over one another, which makes it soft and slippery.
- Graphite conducts electricity because one electron per atom is free to move, and it is used in pencils, electrodes and as a lubricant.
- Fullerene is a spherical form in which carbon atoms are arranged like a football.
- Coal, charcoal, coke and lampblack are impure amorphous forms of carbon.
- Carbon dioxide in the atmosphere is a greenhouse gas that traps heat and warms the planet.
| Allotrope | Structure | Key Property |
|---|---|---|
| Diamond | Each atom bonded to four, rigid | Hardest, non conductor |
| Graphite | Layers, each atom bonded to three | Soft, conducts electricity |
| Fullerene | Spherical cage | Hollow molecular structure |
Catenation — the ability of an element's atoms to bond with one another to form long chains and rings.
Hindi me samjhein
हीरा और ग्रेफाइट दोनों शुद्ध कार्बन हैं, फिर भी एक सबसे कठोर और दूसरा मुलायम है। कारण संरचना है - हीरे में त्रिविमीय जालक और ग्रेफाइट में फिसलती परतें।
Exam me kaise aata hai
- The ability of carbon to form chains is called — catenation
- Which allotrope of carbon conducts electricity — graphite
- The hardest natural substance is — diamond
- Compounds with the same formula but different structures are — isomers
UPSC/State PSC ke liye
- Diamond and graphite differ so completely because structure, not composition, decides physical properties in allotropes.
- Graphite conducts and lubricates for the same reason: the layered bonding leaves one electron free and lets the layers slide.
Yahan confuse hote hain
✗ Diamond conducts electricity | Diamond does not conduct; graphite does | ✓
✗ Allotropes are different elements | They are different forms of the same element | ✓
✗ Carbon forms ionic bonds | Carbon forms covalent bonds by sharing electrons | ✓
Ek nazar me
- Catenation and tetravalency explain the huge number of carbon compounds.
- Carbon bonds covalently, so its compounds conduct poorly and melt at low temperature.
- Diamond is hardest and non conducting; graphite is soft and conducting.
- Fullerene is the spherical allotrope; isomers share a formula but differ in structure.