• Drop a crystal of copper sulphate or potassium permanganate into a glass of hot water and another containing cold water. Do not stir the solution. Allow the crystals to settle at the bottom.
• What do you observe just above the solid crystal in the glass?
• What happens as time passes?
• What does this suggest about the particles of solid and liquid?
• Does the rate of mixing change with temperature? Why and how?
NCERT Class 9th Science Ch 1 Matter in Our Surroundings