Which of the following is a heterogeneous mixture? 1 pointairsalt watersteelsoil

The heterogeneous mixture from the options provided is soil.

Here's why:

1. Air: It is a homogeneous mixture because the composition is uniform throughout. It mainly consists of nitrogen and oxygen with small amounts of other gases.

2. Salt Water: It is also a homogeneous mixture. When salt is dissolved in water, it spreads evenly throughout the solution.

3. Steel: It is a homogeneous mixture as well. It is an alloy made up of iron and carbon and the composition is the same throughout.

4. Soil: It is a heterogeneous mixture because its composition can vary greatly. It can contain various organic materials, minerals, water, air, and living organisms. The composition is not uniform throughout.