1.1. Oxides are compounds which usually contain oxygen combined with one other element.

Oxides are classified as follows.

Complete Table 2.1 to describe the oxides of the elements of the third period of the Periodic Table from sodium to sulfur.

Table 2.1

1.2. Some of the oxides produced can react with water. 

i) Write an equation for the reaction of each of these oxides with water.

Na₂O ..........................................................................................................................................................................

SO₂    ..........................................................................................................................................................................

[2]

ii) What is the pH of the resulting solution in each case? Na₂O .....................................

SO₂   .....................................

[1]

1.3. Give the oxidation number for the Period 3 element in each oxide.

Na₂O ...................................

SO₂   ...................................

1.4. The melting points of the two Period 3 oxides are displayed in Table 2.2. 

Table 2.2 

Explain the difference in melting points.

You should refer to the structure and bonding of each substance.