Give an example to illustrate that metallic oxides are generally basic in nature. [2 marks]

$\bullet$ When a ribbon of magnesium metal is burnt in the air, magnesium oxide is formed in the form of white powdery ash. [1 mark]
$\bullet$ When this ash is dissolved in water and a red litmus paper is dipped in the solution, the colour of the red litmus paper turns blue. This shows that magnesium oxide is basic in nature. [1 mark]