A Pinch of Salt


Science investigations need to be fair tests.

You only change one thing - everything else must be kept the same.

What is the best way to get salt from salt water?

Suppose you wanted to find out if using a fan would make the water evaporate quicker than just leaving it.

Which of these would you compare for it to be a fair test?

Burner compared with fan

Dryer compared with dish

Fan compared with dryer