Draw the Lewis (electron dot) structure of the ammonia molecule.

The Lewis (electron dot) structure of the ethanedioate ion is shown below.

Outline why all the C–O bond lengths in the ethanedioate ion are the same length and suggest a value for them. Use section 10 of the data booklet.

Draw the Lewis (electron dot) structure of the ethanedioate ion, ^–OOCCOO^–.

Sketch the Lewis (electron dot) structure of the P₄ molecule, containing only single bonds.

Deduce the Lewis (electron dot) structure and molecular geometry of PCl₃.

Deduce one resonance structure of ozone and the corresponding formal charges on each oxygen atom.

What are the predicted electron domain geometries around the carbon and both nitrogen atoms in urea, (NH₂)₂CO, applying VSEPR theory?

Draw two Lewis (electron dot) structures for BrO₃⁻.

Draw the Lewis (electron dot) structure for BrO₃⁻ that obeys the octet rule.

Which combination describes the sulfate(IV) ion, SO₃^2– (also known as sulfite ion)?

Ammonia reacts reversibly with water.
$$\text{N}{\text{H}}_{\text{3}}\text{(g)}+{\text{H}}_{\text{2}}\text{O(l)}\rightleftharpoons {\text{NH}}_{\text{4}}^{+}\text{(aq)}+\text{O}{\text{H}}^{-}\text{(aq)}$$
Explain the effect of adding ${\text{H}}^{+}\text{(aq)}$ ions on the position of the equilibrium.

The melting point of diamond at 1 × 10⁶ kPa is 4200 K (in the absence of oxygen).

Suggest, based on molecular structure, why graphene has a higher melting point under these conditions.

Lewis structures show electron domains and are used to predict molecular geometry.

Deduce the electron domain geometry and the molecular geometry for the NH₂⁻ ion.

Show that graphene is over 1600 times stronger than graphite.

The structural formula of urea is shown.

Predict the electron domain and molecular geometries at the nitrogen and carbon atoms, applying the VSEPR theory.

State the type of bond formed when chloramine is protonated.

Draw a Lewis (electron dot) structure of chloramine.

Predict with a reason, whether the molecule PF₃ is polar or non-polar.

Estimate the H−N−H bond angle in methanamine using VSEPR theory.

Outline why all the C–O bond lengths in the ethanedioate ion are the same length and suggest a value for them. Use section 10 of the data booklet.

Draw a Lewis (electron dot) structure for ozone.

Deduce the Lewis (electron dot) structure of ethyne.

Estimate the H−N−H bond angle in methanamine using VSEPR theory.

Draw the Lewis (electron dot) structures of PF₃ and PF₄⁺ and use the VSEPR theory to deduce the molecular geometry of each species.

State the electron domain geometry around the nitrogen atom and its hybridization in methanamine.

What is the structure and bonding in SiO₂(s)?

Carbon and silicon are elements in group 14.

Explain why CO₂ is a gas but SiO₂ is a solid at room temperature.

Draw a Lewis (electron dot) structure of chloramine.

(i) Suggest why incomplete combustion of plastic, such as polyvinyl chloride, is common in industrial and house fires.

(ii) Phthalate plasticizers such as DEHP, shown below, are frequently used in polyvinyl chloride.

With reference to bonding, suggest a reason why many adults have measurable levels of phthalates in their bodies.

Draw the Lewis (electron dot) structures of PF₃ and PF₅ and use the VSEPR theory to deduce the molecular geometry of each species including bond angles.

Predict whether the molecules PF₃ and PF₅ are polar or non-polar.

Identify a value from the table which can be used to support the information about graphene given below.

Electrons in a solid are restricted to certain ranges, or bands, of energy (vertical axis). In an insulator or semiconductor, an electron bound to an atom can break free only if it gets enough energy from heat or a passing photon to jump the “band gap”, but in graphene the gap is infinitely small.

Diamond, graphene, and graphite are all network solids.

Suggest, giving a reason, the electron mobility of diamond compared to graphene.

The structural formula of urea is shown.

Predict the electron domain and molecular geometries at the nitrogen and carbon atoms, applying the VSEPR theory.

Deduce the molecular geometry of chloramine and estimate its H–N–H bond angle.

Molecular geometry:

H–N–H bond angle:

Sketch the Lewis (electron dot) structure of the P₄ molecule, containing only single bonds.

Graphene is two-dimensional, rather than three-dimensional, material.

Justify this by using the structure of graphene and information from the table.

Draw the Lewis (electron dot) structure of hydrogen sulfide.

Deduce the Lewis (electron dot) structure and molecular geometry of sulfur dichloride, SCl₂.

Explain the electron domain geometry of SO₃.

Which combination correctly describes the geometry of the carbonate ion, ${{\mathrm{CO}}_3}^{2-}$?

Deduce the Lewis (electron dot) structure of ethyne.

Deduce the Lewis (electron dot) structure and molecular geometry of sulfur tetrafluoride, SF₄, and sulfur dichloride, SCl₂.

State, giving a reason, the shape of the dinitrogen monoxide molecule.

Outline two differences between the bonding of carbon atoms in C₆₀ and diamond.

Explain why C₆₀ and diamond sublime at different temperatures and pressures.

Deduce the molecular geometry of chloramine and estimate its H–N–H bond angle.

Molecular geometry:

H–N–H bond angle:

Which molecule is most polar?

A.  ${\mathrm{CHF}}_3$

B.  ${\mathrm{CF}}_4$

C.  ${\mathrm{CClF}}_3$

D.  ${\mathrm{CCl}}_4$

Deduce a Lewis (electron dot) structure of the nitric acid molecule, HNO₃, that obeys the octet rule, showing any non-zero formal charges on the atoms.