Is vegetable oil an element, a compound, a homogeneous mixture, or a heterogeneous mixture?

The answer is vegetable oil is a homogeneous mixture.

It has consistency throughout and there is no need to shake it before use, it has same proportions of its components throughout that is in a homogeneous mixture. But in a heterogeneous mixture proportion of different component vary throughout the sample  So, vegetable oil is considered as a homogeneous mixture.

it should have an internal chamber and two thermometers sticking out of the top. the internal chamber will also be closed off from the outside.