The Periodic Table: chemical periodicity — Chemistry 9701 AS & A Level Question & Worked Solution

(a(i))

Using the elements in this list, identify one that floats on cold water and reacts with it readily. State the element’s symbol.

(a(ii))

From this list of elements, identify one that forms an oxide acting as a reducing agent. Give the symbol of the element.

(a(iii))

From this list of elements, identify the one with the lowest first ionisation energy. Give the symbol of the element.

(a(iv))

From this list of elements, identify the element that has a giant molecular structure and forms an oxide with a simple molecular structure. Give the symbol of the element.

(a(v))

From this list of elements, identify the Period 3 element (Na to Ar) that forms the smallest anion. Give the symbol of the element.

(a(vi))

From this list of elements, identify the Period 3 element (Na to Ar) that forms a chloride with a low melting point and an oxide with a very high melting point. Give the symbol of the element.

(b(i))

Using the Period 3 elements (Na to Ar), identify an oxide that shows no reaction with water even after being left in it for a long time. Give the oxide formula.

(b(ii))

Using the Period 3 elements (Na to Ar), identify an oxide that dissolves readily in water and gives a strongly alkaline solution. Give the oxide formula.

(b(iii))

Using the Period 3 elements (Na to Ar), identify two acidic oxides made by the same element. Give the oxide formulae.

(b(iv))

Using the Period 3 elements (Na to Ar), identify an oxide that is amphoteric. Give the oxide formula.

(c(i))

Fluorine reacts with other Group VII elements to form several compounds. Two examples and their boiling points are given: $\text{ClF}_3$ (boiling point $12\,^{\circ}\text{C}$) and $\text{BrF}_3$ (boiling point $127\,^{\circ}\text{C}$). The two molecules have similar electronic configurations. Draw a dot-and-cross diagram showing only the outer electrons for the bonding in $\text{ClF}_3$.

(c(ii))

The two molecules are shaped the same way. Explain why their boiling points differ so much.

(c)

Fluorine reacts with other Group VII elements to make a number of different compounds. The table lists two such compounds and their boiling points: $\text{ClF}_3$ (12 ^{\circ}C) and $\text{BrF}_3$ (127 ^{\circ}C).

The Periodic Table: chemical periodicity — practice question

Worked solution & mark scheme