Question

which of the following is heterogeneous? a air b water c oil and water d steel

Explanation:

A heterogeneous mixture has non - uniform composition. Air is a homogeneous mixture of gases. Water (pure) is a compound, not a mixture. Steel is a homogeneous alloy. Oil and water do not mix uniformly; they form separate layers, so it is a heterogeneous mixture.

Answer:

C. Oil and water