Pakistan MCQs

Four equivalent bonding directions correspond to sp3 hybridization.
The ideal geometry is tetrahedral.

Each carbon has three sigma-bonding regions.
The remaining p orbitals form the pi bond.

Noble gases have filled valence shells in their common ground states.
They are generally unreactive.

Increasing nuclear charge pulls electrons closer within the same main shell.
Effective nuclear attraction generally increases across a period.

Additional electron shells are added down a group.
This outweighs the increased nuclear charge.

Effective nuclear charge generally increases across a period.
Electrons are therefore harder to remove, with some exceptions.

Valence electrons are farther from the nucleus and more shielded down a group.
They are generally easier to remove.

Forming Na+ removes the outer 3s electron.
The cation is smaller than the neutral atom.

Adding an electron increases electron-electron repulsion.
The anion is larger than the neutral atom.

Ionic bonding follows electron transfer and ion formation.
The resulting cations and anions attract in a lattice.

Covalent bonds commonly form between nonmetal atoms.
Shared electrons are attracted to both nuclei.

Metallic bonding explains conductivity and malleability.
Valence electrons move through the metal lattice.