Answer:
1. Milk - Homogeneous - cause only one phase(milk) is visible
2. Hydrogen - Elements - cause it's the only element without neutron
3. Sand mixed with water - Heterogeneous - cause it consists visibly different phases (sand&water)
4. Carbon dioxide - Compounds - cause it is the combination of one particle of carbon and two particle or oxygen
5. Milk and oat - Heterogeneous - cause components (milk&oat) can be seen easily
correct me if i'm wrong, have a nice day!!
