Properties of Matter - Class 7 Science Revision Notes

• Methods of Separating Mixtures.
  • Magnetic Materials

Matter is anything that occupies space and has mass.

A solute-This is the solid which dissolves in a liquid.

A solvent-Thus is the liquid in which the solid dissolves in.

A solution-This is what is formed when solute and solvent are mixed completely.

Soluble solids:-This are solids that dissolves completely in liquids.

Insoluble solids:-These are solids that do not dissolve in liquids when they are mixed.

Miscible liquids:-This are liquids that mix to form a uniform solution eg water and milk,water and spirit, cooking oil and paraffin etc.

Immiscible liquids:-This are liquids that when put together and shaken still forms layers eg water and paraffin.

Methods of Separating Mixtures.

1. Picking:-Involves use of hands to pick big solid particles from a mixture eg mixture of maize and beans, mixture of Stones from rice etc.
2. Winnowing:- Used i separation of light solid particles from the heavy ones using the wind eg a mixture of rice and husk, a
   mixture of sorghum from the chaffs etc.
3. Sieving:- Used in separating mixture of small and large solid particles where the small particles passes through the sieve
   leaving behind the big ones eg mixture of maize and millet.
4. Use of magnet:- Used in separating magnetic materials from non magnetic materials eg Flour and iron fillings
5. Decanting:-Used to separate an insoluble solid from a liquid by gently pouring out the liquids eg mixture water and cooked
   beans.
6. Filtering:- This involves using a filter paper or a cloth to separate a mixture eg a mixture of soil and water
   NB:-The water obtained from filtering is not safe for drinking as it may contain traces of the mixtures and also germs its
   therefore advisable to boil it again

Evaporation:-This is a method that is used to separate a mixture of soluble solid from a liquid but only the solidis recovered.

Home made water filter

Magnetic Materials

TINSCCA

• Tin
• Iron
• Nickel
• Steel
• Chromium.
• Cobalt
• Alnico