Why does a carbon atom share electrons rather than gain or lose four electrons to attain a noble gas configuration?

1. Losing four electrons would give a C4+ ion; its small size and high charge make it unstable. 2. Gaining four electrons would give a C4- ion; nuclear charge +6 cannot hold 10 electrons, so it is unstable. 3. By sharing four valence electrons, both atoms reach a noble gas configuration with no net charge. 4. Atoms stay electrically neutral and gain stability, so sharing is favoured. 5. Rule out B: carbon does not gain four electrons easily; that C4- route is the unstable one rejected in step 2. 6. Rule out C: sharing forms covalent bonds, not ionic bonds, in carbon compounds. 7. Rule out D: forming covalent bonds does involve energy, so the zero-energy claim is false. _Source: Balbharati (Maharashtra Board) Class 10 Science & Technology, Ch 9 "Carbon Compounds", p.120_