GENERAL KNOWLEDGE

Detailed explanation-1: -Carbon has four valence electrons, so it can achieve a full outer energy level by forming four covalent bonds. When it bonds only with hydrogen, it forms compounds called hydrocarbons. There are millions of known carbon compounds, and carbon is the only element that can form so many different compounds.

Detailed explanation-2: -Since carbon has 4 valence electrons, It forms 4 covalent bonds with other molecules to complete its octet; therefore, option b. is correct. Carbon can share up to three of its four valence electrons with a single atom (so long as it also has three valence electrons to share).

Detailed explanation-3: -Carbon forms four covalent bonds by sharing its four valence electrons with four univalent atoms, e.g. hydrogen.

Detailed explanation-4: -The four covalent bonding positions of the carbon atom can give rise to a wide diversity of compounds with many functions, accounting for the importance of carbon in living things. Carbon contains four electrons in its outer shell. Therefore, it can form four covalent bonds with other atoms or molecules.

Detailed explanation-5: -The fourth bond (quadruple bond) if formed would be pointing away from the two carbons. In order for this bond to exist, the other three bonds need to be tremendously bent and this is energetically very unfeasible. This strain thus resists the formation of the quadruple bond.