Bond it like Beckham
This type of bond forms through the complete transfer of electrons between atoms.
Ionic Bond
State the shape of a molecule with four bonding pairs and no lone pairs.
Tetrahedral (e.g. CH₄).
The electrostatic attraction between metal cations and delocalized electrons is called ________.
Metallic bonding.
Type of bonding in cooking salt and copper wire respectively.
NaCl – ionic; Cu – metallic.
True or False: Ionic bonding only occurs between metals and non-metals.
False — can occur between polyatomic ions too (e.g., NH₄Cl).
Explain why NaCl and MgO both form crystalline solids, but MgO has a much higher melting point.
Mg²⁺ and O²⁻ have greater charge → stronger electrostatic attraction → higher lattice energy.
What causes the bent shape of H₂O, according to VSEPR theory?
Two lone pairs repel bonding pairs, compressing bond angle to ~104.5°.
Why are metals good conductors of electricity?
Delocalized electrons move freely throughout the lattice.
Why is diamond used in cutting tools while graphite is used as a lubricant?
Diamond’s 3D covalent structure is rigid; graphite’s layered structure slides easily.
Which molecule defies the octet rule — BF₃, CH₄, or H₂O?
BF₃ (incomplete octet).
Which of these bonds is most polar: H–Cl, H–Br, or H–I?
H–Cl (largest electronegativity difference).
Predict and explain the shape of BF₃.
Trigonal planar — three bonding pairs, no lone pairs.
Arrange these in increasing bond strength: metallic (Na), covalent (H₂), ionic (MgO).
H₂ < Na < MgO.
Why does metallic bonding explain both high melting points and electrical conductivity in metals?
Strong attraction between ions and delocalized electrons; free electron movement conducts current.
Why is CO a poor conductor despite having polar bonds?
Electrons are localized in discrete covalent bonds — no delocalized movement.
Covalent bonds are called “directional.” What does this mean in terms of electron density?
Electron density is concentrated between two nuclei, creating specific geometric orientations.
Explain why NH₃ has a smaller bond angle than CH₄.
Lone pair on N exerts greater repulsion → 107° vs 109.5°.
Why do ionic compounds tend to be brittle, but metals are malleable?
Shifting ionic layers bring like charges together → repulsion; metallic bonds are non-directional.
Which bonding type gives rise to materials that shatter easily but have high melting points?
Ionic bonding.
Predict what happens to metallic bonding strength as you move across Period 3 from Na → Al.
Increases — more valence electrons and smaller cation radius → stronger attraction.
Explain why aluminum chloride (AlCl₃) behaves as an ionic compound when molten but covalent when gaseous.
Al³⁺ has high polarizing power; distorts Cl⁻ electron cloud → covalent in vapor phase, ionic in solid.
The CO₂ molecule has two double bonds. Why is it linear rather than bent?
Bond pairs on opposite sides of C repel equally → 180° linear shape.
Explain why giant covalent structures (like SiO₂) have higher melting points than metals like Cu.
Strong directional covalent bonds in all dimensions require much more energy to break.
What makes metals like copper malleable, while ionic solids like NaCl are brittle, at the atomic level?
Metallic bonds are non-directional; ionic bonds shift due to repulsion when layers move.
A chemist says: “Metals are giant covalent structures.” Correct or incorrect — justify.
Incorrect — metals have delocalized electrons, not directional covalent bonds.