1. Solid-Solid Mixture

A mixture made by physically combining two or more solid substances that do not dissolve in each other.

• Sand – coarse, irregular particles
• Salt – fine cubic crystals
• Mustard seeds – small round yellow seeds
• Rice grains – larger elongated grains

2. Mixing & Stirring

Stirring distributes the particles among each other. No chemical change occurs — components stay separate.

3. Key Observations

• Different sizes & shapes → visible layering or mixing
• Can be separated again by physical methods
• Stirring makes it look more uniform temporarily

4. Common Examples

• Sand + Salt
• Rice + Mustard seeds
• Grains + small stones / pulses + chaff

5. Separation Techniques

• Hand picking — rice & mustard (different shape/size)
• Sieving — salt passes through fine mesh, sand stays
• Winnowing — very light particles (not simulated here)