For Grade 5 class

2. PHYSICAL PROPERTIES
• PHYSICAL PROPERTIES CAN BE OBSERVED OR MEASURED WITHOUT CHANGINGTHE
COMPOSITION OF THE SUBSTANCE.
• AN EXAMPLE IS ODOR. WHEN YOU SMELL WATER OR ISOPROPYL ALCOHOL, NEITHER OF THESE
SUBSTANCES CHANGES INTO SOMETHING ELSE. THEY REMAIN WATER AND ISOPROPYL
ALCOHOL. SIMILARLY, WHEN WATER AND ISOPROPYL ALCOHOL EVAPORATE,THEY DO NOT
CHANGE INTO SOMETHING ELSE. THEY MOVE FROM LIQUID INTO GAS, BUTTHE WATER IS STILL
WATER AND THE ALCOHOL IS STILL ALCOHOL. BECAUSE THESE SUBSTANCESDO NOT CHANGE
INTO DIFFERENT SUBSTANCES,
• THE PROPERTIES OF ODOR AND SPEED OF EVAPORATION ARE PHYSICAL PROPERTIES.

3. HARDNESS
• HARDNESS IS A MEASURE OF HOW
RESISTANT SOLID MATTER IS TO VARIOUS KINDS
OF PERMANENT SHAPE CHANGE WHEN A
COMPRESSIVE FORCE IS APPLIED. SOME
MATERIALS, SUCH AS METAL, ARE HARDER THAN
OTHERS.
DID YOU KNOW?
WURTZIDE BORON NITRIDE IS HARDER THAN
DIAMONDS. ONLY SMALL AMOUNTS OF THESE
EXISTS.

4. BRITTLENESS
• A MATERIAL IS BRITTLE IF, WHEN SUBJECTED
TO STRESS, IT BREAKS WITHOUT SIGNIFICANT
DEFORMATION (STRAIN). BRITTLE MATERIALS
ABSORB RELATIVELY LITTLE ENERGY PRIOR TO
FRACTURE, EVEN THOSE OF HIGH STRENGTH.
BREAKING IS OFTEN ACCOMPANIED BY A SNAPPING
SOUND. BRITTLE MATERIALS INCLUDE MOST
CERAMICS AND GLASSES (WHICH DO NOT DEFORM
PLASTICALLY) AND SOME POLYMERS, SUCH
AS PMMA AND POLYSTYRENE.

5. FLEXIBILITY
• FLEXIBILITY IS THE PROPERTY OF BEING ABLE TO
BEND WITHOUT BREAKING

6. ELASTICITY
• THE ABILITY OF A BODY TO RESIST A DISTORTING
INFLUENCE OR STRESS AND TO RETURN TO ITS
ORIGINAL SIZE AND SHAPE WHEN THE STRESS IS
REMOVED. SOLID OBJECTS
WILL DEFORM WHEN FORCES ARE APPLIED ON
THEM. IF THE MATERIAL IS ELASTIC, THE OBJECT
WILL RETURN TO ITS INITIAL SHAPE AND SIZE
WHEN THESE FORCES ARE REMOVED.

7. CONDUCTIVITY
• ABILITY TO LET HEAT AND ELECTRICITY TO PASS
THROUGH .

8. MALLEABILITY
• MATERIAL'S ABILITY TO DEFORM
UNDER COMPRESSIVE STRESS; THIS IS OFTEN
CHARACTERIZED BY THE MATERIAL'S ABILITY TO
FORM A THIN SHEET BY HAMMERING OR
ROLLING.

9. DUCTILITY
• DUCTILITY IS A SOLID MATERIAL'S ABILITY TO
DEFORM UNDER TENSILE STRESS; THIS IS OFTEN
CHARACTERIZED BY THE MATERIAL'S ABILITY TO
BE STRETCHED INTO A WIRE.

10. CHEMICAL PROPERTIES
• AS YOU LOOK AT THE THINGS AROUND YOU, IT IS EASY TO SEE MANY OFTHEIR PHYSICAL PROPERTIES
SUCH AS COLOR, SHAPE, AND SIZE. SOME PROPERTIES OF A SUBSTANCE ARE NOT AS OBVIOUS, UNLESS
THE SUBSTANCE HAS CHANGED COMPOSITION AS A RESULT OF A CHEMICALREACTION. A CHEMICAL
PROPERTY IS THE ABILITY OF A SUBSTANCE TO COMBINE WITH OR CHANGE INTO ONE OR MORE OTHER
SUBSTANCES.

11. COMBUSTIBILITY AND FLAMMABILITY
• COMBUSTIBILITY IS THE ABILITY OF A MATERIAL
TO BURN
• FLAMMABILITY IS THE ABILITY OF THE MATERIAL
TO IGNITE OR CATCH FIRE EASILY

12. BIODEGRADABILITY
• ABILITY OF A MATERIAL TO EASILY DECOMPOSE