Question

A mixture consists of sand, salt, and iron filings. Which of the following instruments or materials would not be useful in separating this mixture?

magnet
filter paper
screen
water

Answer 1

This is certainly screen.
Magnets, filter paper, and water are all useful in seperating the mixture, as magnet can seperate the iron, the salt would dissolve into the water, and it can obviously be filtered with- you guessed it- filter paper.
However, I don't see where the screen woul fit in here. So this would be my answer.

Answer 2

thx again

Answer 3

You're welcome. You know what to do. ^^