Start here

A cook picks small stones out of rice. Then she washes the rice.

This is Chapter 9 of your NCERT book. It is Methods of Separation in Everyday Life.

Why separate, and six ways to do it

• Why separate — keep what you want, remove what you do not.
• By size — sieving and handpicking.
• By weight — winnowing, with moving air.
• Settling — heavy bits sink when left still.
• Filtering — catches solid bits. It cannot catch what has dissolved.
• Getting it back — evaporate the water. The dissolved solid stays.
• With a magnet — pulls iron out. Leaves the sawdust.

Each method uses one real difference between the parts.

Salt in water is dissolved: you cannot see it. Sawdust is the fine powder left when wood is cut.