All of the following processes involve a separation of either a mixture into substances or a compound into elements. For each, decide whether a physical process or a chemical reaction is required.

a. Sodium metal is obtained from the substance sodium chloride.

b. Iron filings are separated from sand by using a magnet.

c. Sugar crystals are separated from a sugar syrup by evaporation of water.

d. Fine crystals of silver chloride are separated from a suspension of the crystals in water.

e. Copper is produced when zinc metal is placed in a solution of copper(II) sulfate, a compound.