1.A two face mixture is a type of mixture in which the components of the mixture are in different states of matter. A good example of a two face mixture is carbonated soft drink. Carbonated soft drink is a mixture of carbon dioxide [which is a gas] and water [which is a liquid]. Another example of a two face mixture is the the mixture of iodine and sodium solution.
2. To separate the mixture of iodine and sodium solution the best separation method to use is sublimation. Sublimation process is used to separate mixtures in which one of the component of the mixture can translate from the solid state to the gaseous state without passing through the liquid state. An example of a solid which can sublime is iodine. The sublimation process involves heating the mixture. On heating, the sublime solid will turn to vapour and escape from the mixture leaving behind the other component. The sublime component will be regained when it cools down.
Because that's where they come from. Coal, oil, and natural gas are the products of dead dinosaurs rotting in the ground under great pressure for millions of years.
