Give an activity to show that metals burn in air to form bases.

Explanation

Take magnesium ribbon and hold it on a flame with the help of tongs. It will be observed that Magnesium burns in air with a brilliant flame to form a white powder of magnesium oxide.
`underset("Magnesium")(2Mg)+ underset("Oxygen")(O_2) rarr underset("Magnesium oxide")(2MgO)`
If this white powder is dissolved in water and red litmus solution is added to it, it will turn blue indicating that magpesium oxide is a basic oxide.
`underset("Magnesium oxide")(2MgO)+ underset("water")(H_2O) rarr underset("(A basic solvent)")underset("Magnesium hydroxide")(Mg(OH)_2)`