Sand remains undissolved in water. Filter paper traps every sand grain, but the available sieve mesh lets every grain through. Which method separates the sand while collecting liquid water below?

• Filtering through paper
• Sieving through mesh
• Evaporating the water

Dry pebbles and sand are mixed together. A sieve has holes that let sand through but hold pebbles back. Which method uses this difference?

• Filtering through paper
• Sieving by particle size
• Evaporating the water

Water in a shallow dish can evaporate without being boiled.

Why does dissolved salt pass through ordinary filter paper?

• Dissolved salt particles fit through the filter openings.
• The salt melts on the paper.
• The salt sticks to the paper first, then falls into the water.

You want separate samples of sand and salt from sand mixed into salty water. You do not need to collect the water. Which plan works?

• Evaporate water, then filter the dry solids
• Sieve the mixture, then filter dissolved salt
• Filter out sand, then evaporate the water

Gravel, sand and salty water are mixed. A sieve traps gravel but passes sand and water. Filter paper traps both solids. Set trapped solids aside without sorting them again. Only what passes through goes to the next stage. Which order recovers gravel, sand and salt separately?

• Filter, then sieve, then evaporate
• Sieve, then filter, then evaporate
• Evaporate, then sieve, then filter

Zara leaves filtered salty water in a shallow dish. Some water evaporates, but clear liquid remains. Which explanation is supported?

• The remaining clear liquid may still hold dissolved salt.
• All the salt has evaporated.
• The filter caught all the salt, leaving only water in the dish.

Tom pours a salt solution through a sieve, expecting salt to stay in it. Which explanation identifies the problem?

• The sieve holes are blocked by salt.
• The salt needs warmer water before sieving.
• Dissolved salt passes through.