CHEMICAL BONDING AND MOLECULAR STRUCTURE
Frequently Asked Questions
A chemical bond is the attractive force that holds atoms or ions together in a molecule or compound due to electrostatic interactions between charged particles.
Atoms form bonds to attain lower potential energy and greater stability, often by achieving a noble gas configuration (octet or duplet).
The octet rule states that atoms tend to gain, lose, or share electrons to acquire eight electrons in their valence shell.
The duplet rule applies to hydrogen and helium, which attain stability with two electrons in their outermost shell.
An ionic bond is formed by complete transfer of electron(s) from one atom to another, resulting in oppositely charged ions held by electrostatic attraction.
A covalent bond is formed by mutual sharing of one or more pairs of electrons between two atoms.
Bond order is defined as half the difference between the number of bonding and antibonding electrons: \( \text{Bond Order} = \frac{N_b - N_a}{2} \).
Higher bond order generally implies stronger bond and shorter bond length.
Bond length is the equilibrium distance between the nuclei of two bonded atoms.
Bond enthalpy is the energy required to break one mole of bonds in gaseous state.
Lattice energy \( U \propto \frac{q_1 q_2}{r} \), where \( q_1, q_2 \) are ionic charges and \( r \) is interionic distance.
Formal charge \( = V - L - \frac{B}{2} \), where \( V \) = valence electrons, \( L \) = lone pair electrons, \( B \) = bonding electrons.
Resonance is the phenomenon in which a molecule cannot be represented by a single Lewis structure but by multiple contributing structures.
Resonance hybrid is the actual structure of a molecule represented as a weighted average of contributing resonance structures.
Valence Shell Electron Pair Repulsion (VSEPR) theory predicts molecular geometry based on repulsion between electron pairs around the central atom.
