The Periodic Table Structured Questions | Cambridge O Level Chemistry

Chemistry 5070 · Question 1[13 marks]

The elements sodium to argon form Period 3 of the Periodic Table.

(a)

Explain why sodium and chlorine are placed in the same period of the Periodic Table.

[1]

(b)

State and explain the trend in atomic radius across Period 3 from sodium to chlorine.

[3]

(c)

The oxides of Period 3 elements show a transition in bonding and chemical character.

[5]

(i)

Identify the bonding type and physical structure in sodium oxide ( $\ce{Na2O}$ ) and sulfur dioxide ( $\ce{SO2}$ ).

[2]

(ii)

Describe an experiment, using universal indicator solution, to distinguish between aqueous solutions of sodium oxide and sulfur dioxide, giving expected observations and pH values.

[3]

(d)

Silicon is a Period 3 element located in Group IV.

[4]

(i)

Describe the structure and bonding of silicon, explaining why it has a very high melting point (1414 °C).

[3]

(ii)

State one practical electrical application of silicon due to its position on the metalloid boundary.

[1]