Which separation techniques will you apply for the separation of the following?

Small pieces of metal in the engine oil of a car.

Which separation techniques will you apply for the separation of the following?

Different pigments from an extract of flower petals.

Which separation techniques will you apply for the separation of the following?

Ammonium chloride from a mixture containing sodium chloride and ammonium chloride.

Which separation techniques will you apply for the separation of the following?

Sodium chloride from its solution in water.

Classify the following as chemical or physical changes:
(i) cutting of trees.
(ii) melting of butter in a pan.
(iii) rusting of almirah.
(iv) boiling of water to form steam.
(v) passing of electric current, through water and the water breaking down into hydrogen and oxygen gases.
(vi) dissolving common salt in water.
(vii) making a fruit salad with raw fruits, and
(viii) burning of paper and wood.