The Period 3 elements, Na to S, all react with oxygen to form oxides.

1. (a)State the trend in acid/base behaviour of the oxides of the Period 3 elements, from Na to S.[1]
2. (b)State and explain the trend, from Na to S, in the maximum oxidation number of the Period 3 elements in their oxides.[2]
3. (c)Sodium oxide and phosphorus(V) oxide both react with water. Name the product of each reaction. [Table with 'reaction' and 'product'][2]
4. (d)Explain why phosphorus(V) oxide has a low melting point of approximately 300°C but magnesium oxide has a high melting point of approximately 2850 °C.[3]
5. (e)Aluminium oxide, Al2O3, reacts separately with both acids and alkalis.
6. (e)(i)Write an equation for the reaction of aluminium oxide with excess aqueous hydrochloric acid.[1]
7. (e)(ii)Write an equation for the reaction of aluminium oxide with excess aqueous sodium hydroxide.[1]
8. (f)Describe the lattice structure of silicon(IV) oxide. Your answer should include reference to the arrangement of the silicon and oxygen atoms and the bonds between them.[2]
9. (g)Sodium oxide and silicon(IV) oxide react to form sodium silicate(IV), Na2SiO3. Sodium oxide is obtained from the thermal decomposition of sodium carbonate. Write equations for the following reactions:
10. (g)(i)sodium oxide with silicon(IV) oxide[1]
11. (g)(ii)the thermal decomposition of sodium carbonate, forming sodium oxide and carbon dioxide.[1]