Question

1. A mixture of oil and water retains the properties of its constituents.
2. Magnetic separation cannot be used to separate a mixture of copper and sulphur
3. Sand particles are separated from gravel ar construction sites using sieving​

Answer 1

Answer:  1. In any mixture the constituents retain the properties of their particles. This is because the formation of mixture does not involve any chemical reaction or formation of the bonds between the constituents and the constituents retains their original properties. Same case is with mixture of water and oil.

2. Magnetic separation can't be used to separate a mixture of copper and sulphur because, Magnet attracts iron only and no other metal. So, a magnet can't be used in this case.

3. The sieve plate or screen with fine holes will let through the finer sand particles and not the larger stones or gravels. Thus stones or gravels are separated from sand.

Answer 2

1. Because oil floats on water.It doesn't get mixed with water.

2. Because neither copper nor sulphur are magnetic materials

3. Because sand particles are smaller than gravel.