Chemical Bonding and Atomic Structure MCQs for NEET — Chemistry Questions with Answers

Carbon can form covalent bonds. A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding. Carbon typically forms four covalent bonds to achieve a full outer shell of electrons, which is known as a stable octet.

Carbon shows tetravalency in its excited state. In its ground state, carbon has the electronic configuration $1s^2 2s^2 2p^2$. In the excited state, one of the 2s electrons is promoted to the 2p orbital, resulting in the configuration $1s^2 2s^1 2p^3$. This allows carbon to form four covalent bonds, utilizing one electron from the 2s orbital and three electrons from the 2p orbitals, making it tetravalent.

In benzene ($C_6H_6$), each carbon is sp2 hybridized, leading to bond angles of $120^ ext{°}$. Similarly, in ethene ($C_2H_4$), the carbons are also sp2 hybridized, resulting in bond angles of $120^ ext{°}$ around each carbon atom.

The compound $ (CH_3)_3 COH $ (tert-butyl alcohol) involves carbon atoms that are all sp^3 hybridized. In this structure, each carbon forms four sigma bonds, which is characteristic of sp^3 hybridization. The central carbon is bonded to three methyl groups and one hydroxyl group, utilizing sp^3 hybrid orbitals for all its bonds.

When the hybridization state of carbon changes from $sp^3$ to $sp^2$ and finally to $sp$, the bond angles increase progressively. In $sp^3$ hybridization, the bond angles are approximately 109.5°. In $sp^2$ hybridization, the bond angles are 120°, and in $sp$ hybridization, the bond angles are 180°. This increase in bond angle is due to the increasing s-character in the hybrid orbitals.

Electronegative difference in KI is more

According to valence-bond theory, oxygen molecule (O2) is paramagnetic. This is due to the presence of two unpaired electrons in its molecular orbital configuration, which makes it attracted to a magnetic field.

Here C - C contain double and triple bond

$NO_3 ^ - and CO_3^ {2-} contains 32 e- so they are iso electric ions Both possess sp^2$ hybridization