SORTING MATERIALS INTO GROUPS | SPEED NOTES | SCIENCE | CBSE | CLASS 6

CBSE Class–VI Subject Science Revision Notes CHAPTER – 4 Sorting Material into Groups Matter : Anything thatoccupies space andhas mass iscalled matter. Objects around us are made up of a large variety of materials. Material : A material is a substance which is usedfor making things. A given material could be usedto make alarge number ofobjects. It isalso possible thatan object could bemade of asingle material orof many different types of materials. GENERAL PRPERTIES OF MATRIAL (A) Apearance : shine( luster orluster ) or Roughness ( non- lustrous ) Allmetals are lustrous , some are moreand some areless. wood, rubber or a piece of rock isnon-lustrous. (B) . Hardness ; Hard and soft Rocks, iron and manymetals are hard. Hard materials maybe : 1. Brittle ;- Which breakinto samller pieces or are powdered when hammered, ex.rock,glass,salt. Malleable : which spread intosheets when beaten . metals aremalleable. Ductile :- theycan be drawninto thin andlong wires. metals are ductile. 2. 3. materials like wood, rubber and fibres aresoft. (C) Thorough visibility :- Transarent :- object through which light may pass .ex. glass some plastis , sugar and salt solution in water. Transluscent :- object through which light may pass partially.ex. milky glass, milk.

Opaque :_ object through which light doesnot pass.ex. wood,metals, rock,wall.

(D) Goodand bad conductor of electricity :- material through which electric current can pass easily are the goodconductors of electricity. metals are goodconductors of electricity. wood, plastic,rubber, corkand certain materials are bad conductors of electricity.electric current doesnot pass through them.

(D) Goodand bad conductor of heat :- Allmetals are goodconductors of heat. wood are badconductors of heat.

(E) combustible substances :- The materials which catch fireon heating arecombustible substance. wood, lastic,fibre and paper arecombustible substance.

(F) SOMEMATERIAL MAY FLOATAND SOME SINKIN WATER. material which sinks inwater is denser than water. material which floats onwater is lessdense than water.

(G) SOLUBILITY O A SUBSTANCES IN WATER. Thesubstnces like saltand sugar , which disappear in water , are saidto be soluble.

The substances which remain as suchand do notdisappear in water are said tobe insoluble in water.

(H) Miscible and Immiscible Liquid :- whentwo liquids aremixed and theydo nort mixedwell, they aresaid to be immiscible. The liquids which mix well withwater are saidto be miscible.

GROUPING OF MATERIALS. Things made from wood Things made fromfibre

Things made from metal Things madefrom ceramic Things made from glass Things made from plastic Things made from rubber things that areliquids such asoil. Materials are grouped together on the basis of similarities anddifferences in their properties. Things are grouped together for convenience andto study theirproperties.

Advantages of classification: (a) Helps in identification of objects. (b) Helps in sortingof objects. (c) Helps in locting things. (d) Makes study ofdifferent objects easyand more meaningful rather than studying each other separately. (e) Helps to understanding similarities and dissimilarties among objects.