Sec 3 Chemistry Chemical Bonding & Structure topical questions

Magnesium (2.8.2) reacts with chlorine (2.8.7) to form magnesium chloride.

1. (a)State how many electrons one magnesium atom loses and how many one chlorine atom gains.[1]
2. (b)Write the formula of magnesium chloride.[1]
3. (c)Name the type of bonding in magnesium chloride.[1]

Complete the table of common molecules.

State the three particles (types of particle) whose arrangement defines each structure: giant ionic, simple molecular, giant molecular, metallic.

Write the formulae of the ionic compounds formed between: (a) K⁺ and Br⁻; (b) Mg²⁺ and F⁻; (c) Al³⁺ and Cl⁻.

Describe, in words, the dot-and-cross diagram for the formation of sodium chloride, including the electron transfer.

Explain why sodium chloride has a high melting point but carbon dioxide is a gas at room temperature, in terms of structure and bonding.

Both diamond and graphite are giant covalent forms of carbon.

1. (a)State how many covalent bonds each carbon atom forms in diamond and in graphite.[1]
2. (b)Explain why graphite is soft and slippery while diamond is hard.[2]
3. (c)Explain why graphite conducts electricity but diamond does not.[2]

A student tests four unknown solids: W conducts only when molten, X never conducts, Y conducts as a solid, Z has a very high melting point and never conducts in any state.

1. (a)Identify the most likely structure type of each solid.[4]
2. (b)State one further test to confirm Z is silicon(IV) oxide rather than diamond.[1]

Copper is used for electrical wiring; sodium chloride is not.

1. (a)Explain in terms of particles why copper conducts electricity.[2]
2. (b)Explain why solid sodium chloride cannot be used, even though it contains charged particles.[2]

An ionic crystal is struck sharply and shatters; a metal block struck the same way dents.

1. (a)Explain the shattering of the ionic crystal in terms of its particles.[3]
2. (b)Explain why the metal dents instead.[2]

Silicon(IV) oxide and carbon dioxide both contain Si–O or C–O links, yet SiO₂ is a solid melting above 1600 °C while CO₂ sublimes at −78 °C.

1. (a)Describe the structure of each substance.[3]
2. (b)Explain the difference in melting behaviour using the structures.[3]

A mystery element E forms an oxide E₂O₃ that is a white solid with a very high melting point.

1. (a)Deduce the charge on the E ion and the group of element E.[3]
2. (b)Identify E if its nucleon number is 27 and it has 14 neutrons; give your reasoning.[3]