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How alkali metals burn in air

Answer Text:
Burning of alkali metals in air
- Alkali metals burn in air with characteristic flame colours to form corresponding metal oxides.
Examples:
-Lithium.
- Burns in air to form lithium oxide as the only product.
Equation:
#4Li(s) + O_2(g) → 2Li_2O(s)#
Sodium:
- Burns in air to with a yellow flame to form sodium oxide as the only product.
Equation:
#4Na(s) + O_2(g) → 2Na_2O(s)#
Note:
- When burned in air enriched with oxygen or pure oxygen sodium burns with a yellow flame to fom sodium peroxide (instead of sodium oxide).
Equation: #2Na(s) + O_2(g) → Na_2O_2(s)#
-Potassium.
- Burns in air with a lilac flame to form potassium oxide as the only product.
Equation:
#4K(s) + O_2(g) → 2K_2O(s)#