I'm trying to look for the answer...
-oil & water - cream & milk
A mixture of oil and water is a mixture, not an element. If by substance you mean not a pure substance (element or compound), then oil and water would be a substance (that is a mixture). If you mean oil and water separately, then oil is a mixture of hydrocarbons, and water is a compound (pure substance).
Oil is a mixture of hydrocarbons.
Oil and vinegar is a heterogeneous mixture.
Water and oil is a heterogeneous mixture. Oil can be separated from water via specific methods. That's why a combination of water and oil is heterogeneous.
Water and oil do not mix with each other. It is a mixture.
A hypothesis about oil and water could have to do with a mixture's properties. For example, you could hypothesize that when water is added to oil, the two substances will remain separate.
The oil-water mixture is not homogeneous.
Yes as The amount of emulsifier in the mixture of water and oil is increased the time taken for the oil and water to separate is increased.
No. Oil and water would form a heterogeneous mixture. A solution is a homogeneous mixture.
It is neither, it is an element
Water and oil is a heterogeneous mixture. Oil can be separated from water via specific methods. That's why a combination of water and oil is heterogeneous.