Answer:

1.MILK- HOMOGENOUS.Whole milk is actually a heterogeneous mixture composed of globules of fat and protein dispersed in water. Homogeneous mixuters are those in which the components are evenly distributed over the major component/constitute of the mixture.

2.HYDROGEN- HOMOGENOUS. As we know that the homogeneous mixture is one in which the chemical composition is consistent throughout

3.SAND MIXED WITH WATER- HETEROGENEOUS. A mixture of sand and water is the best example of heterogeneous mixture. A mixture in which the composition is not uniform throughout the mixture then it is said to be a heterogeneous mixture.

4.CARBON DIOXIDE- HOMOGENOUS. Sometimes gases can be dissolved in liquids. For example, carbonated drinks have carbon dioxide dissolved in water, making a homogeneous mixture.

5.MILK AND OATMEAL- heterogeneous.