Download Changes and Particle Theory

Changes and
Particle Theory
• What is the colour of these solids ?
colourless
Physical Properties
• Colour is one of the physical properties of a
substance.
• Can you tell me some other physical
properties of a substance ?
• State
• Melting point
• Boiling point
• Taste
colour
State
Melting
point
Table salt
Water
Chlorine
colourless
colourless
Pale green
Solid
Liquid
Gas
0C
-101C
808C
Water
water vapour
• Physical change is a change in which no
new substances are formed.
Examples of physical change
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•
•
•
•
•
•
•
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Dissolving salt in water
Water turns into ice
Ice-cream changes into liquid
Evaporation
Boiling
Condensation
Freezing
Melting
Sublimation
Wood
carbon dioxide
A change is a change in which one or more new
substances are formed.
Burning always is a chemical change.
Decide whether each of the
following is physical or
chemical change:
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•
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Breaking a glass cup
Burning coal in air
Frying an egg
Evaporating salt solution to dryness
Particle theory of Matter
• Iodine(碘) particles leave the solid and mix
with the alcohol particles.
Three States of Matter
• Solids,
• Liquids,
• Gases
Which of following is a chemical property ?
A.
B.
C.
D.
Tastes like alcohol.
Burns in air.
Mixes in all proportions with water.
Colourless.