Chromatography and fractional distillation can be used to separate compounds. In which type of separation is a thermometer needed for checking that complete separation has
occurred?
A chromatographic separation of two colourless solids
B chromatographic separation of two solids of different colours
C fractional distillation of two colourless liquids
D fractional distillation of two liquids of different colours

Arock can be broken down into different kinds of substances by physical processes. no chemical reactions are needed to separate different parts of a rock into pure substances. this is because a rock is a(n)

Imagine that you’re getting ready to move to a new city. when people move, they are influenced by push factors and pull factors, and you have many reasons for your move. which of the following factors is an example of a pull factor? a. wanting to move because you’ve found a great new school somewhere new b. needing to move because there are not enough resources in your old hometown c. being forced to move because your old home is gone d. having to move because there are no jobs in your current hometown

An alloy contains 66 g of pure zinc. what is the percentage of zinc in the alloy? express your answer to two significant figures and include the appropriate units.