Jan 2024

Question 1

1.1. Describe the bonding in solid gallium. (2)

Answer 1

(1) attraction between (lattice of) positive (metal) ions or attraction between (lattice of) Ga3+ ions

(2) and delocalised electrons

Question 2

2.6. Chlorine gas is bubbled into an aqueous solution of potassium iodide. Give 1 observation. (1)

Answer 2

black solid or black precipitate or brown solution

Question 3

4.2. The C–F bond is polar. Explain why CF4 is a non-polar molecule. (2)

Answer 3

(1) the molecule is tetrahedral or symmetrical

(2) (so the) dipoles cancel out

Question 4

6.1. State why the atomic radius of barium is larger than the atomic radius of calcium. (1)

Answer 4

more (electron) shells or more energy levels

Question 5

7.1. Identify the element in Period 3 with the lowest melting point. (1)

Answer 5

Argon