Question

In which situation will screening be used to separate a mixture?

if the mixture is a solid suspended in a gas
if the components have different boiling points
if the mixture is a solid dissolved in a liquid
if the components have different colors

Answer 1

Screening (or sieving) is a method typically used to separate solid particles based on size. Therefore, it will be used to separate a mixture in the situation where **if the components have different colors**.

While screening is not primarily based on color, if you are visually separating solids of different colors (like grains or sand of different colors), it can be performed as a screening process. However, if you strictly define screening, the best fit would generally be based on size differences rather than color.

For clarity:
- **If the mixture is a solid suspended in a gas**: This situation often requires filtration rather than screening.
- **If the components have different boiling points**: This would typically involve distillation.
- **If the mixture is a solid dissolved in a liquid**: This would require filtration or evaporation.
- **If the components have different colors**: This could involve screening if they can be physically separated by visual identification.

Overall, screening is best for separating solids based on size rather than color.