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Question
The elements whose oxides can turn litmus solution blue are ______.
Options
carbon and sulphur
sodium and carbon
potassium and magnesium
magnesium and sulphur
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Solution
The elements whose oxides can turn litmus solution blue are potassium and magnesium.
Explanation:
Litmus solution turns blue in the presence of a base. Metals like potassium and magnesium react with oxygen to form metallic oxides (K2O and MgO), which are inherently basic and dissolve in water to yield alkaline solutions. Conversely, non-metals like carbon and sulphur produce acidic oxides (CO2 and SO2) that would instead turn litmus paper red.
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