Chemistry — Unit 1 — Test 2

EA values are always more negative than ionization energies.

Be and Mg have near‑zero first EA because adding to a filled ns^2 subshell is unfavorable.

N has near‑zero EA because it would pair electrons into a half‑filled p subshell, which is favorable.

EA increases uniformly down a group due to diffuse orbitals.

Trigonal planar with one axial lone pair.

T‑shaped with two axial lone pairs.

Bent due to two lone pairs.

Linear with three equatorial lone pairs on Xe.

All four S–F bonds are equal by symmetry.

Equatorial S–F bonds are longer because they have more 90° interactions.

Axial S–F bonds are longer than equatorial due to greater 90° interactions and lone‑pair repulsion.

Axial bonds are shorter because axial positions are less crowded.

AX2E3; linear.

AX3E2; T‑shaped.

AX5E; square pyramidal.

AX3E; trigonal pyramidal.

Octahedral (AX6).

Square antiprism.

Trigonal prism.

Pentagonal bipyramidal (AX7).

Metallic bonding among iodide ions.

Three‑center, four‑electron (3c–4e) π‑type bonding involving p orbitals.

Classical 2c–2e bonds with no delocalization.

dsp3 hybridization on the central iodine with two axial bonds and three lone pairs.

CF4

CH4

CCl4

CH3F

C–H

C–F (trans)

All bonds have equal s‑character in CH2F2.

C–F (cis)

All angles are 109.5°.

∠H–C–H > ∠H–C–F > ∠F–C–F

∠F–C–F > ∠H–C–F > ∠H–C–H

∠H–C–F = ∠F–C–F > ∠H–C–H