Properties of Materials And Chemical Reactions. S1-2-07 Investigate the characteristic properties of...
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Transcript of Properties of Materials And Chemical Reactions. S1-2-07 Investigate the characteristic properties of...
Properties of Materials
And Chemical Reactions
S1-2-07 Investigate the characteristic properties of metals, non-metals, and metalloids and classify elements according to these properties.
S1-2-12 Differentiate between physical and chemical changes.
Vocabulary & PeopleState/Phase Melting Point Boiling Point
Lustre Malleability Ductility
Solubility Conductivity Combustion
Corrosion Oxidation Hydration
Metalloids Precipitate
Physical properties • Used to describe and classify matter• Traits that can be observed or measured without
changing the composition of matter
State/phase – solid, liquid or gas (normally)
Hardness – how easy it is to scratch or dent
Viscosity – how easy it flows
Melting point – unique temperature needed to change from solid into liquid
Boiling point – unique temperature needed to change from liquid into gas
Lustre – shiny or dull
Malleability – how easy to bend or flatten (opposite – brittle)
Ductility – how easy to pull into a wire
Solubility – does it dissolve in water
Conductivity – does it transfer heat/electricity
Other examples of Physical Properties:
Chemical properties • Describes how a substance will react chemically• Cannot be observed without changing the
original material
Combustion – does it burn or ignite
Corrosion – does it react with acids
Oxidation – does it react with air
Hydration – does it react with water
Heating – does it react to heat
Don’t confuse “melting” with reacting with heat – one is a phase change, the other is changing into a new compound
Metals • Most common form of matter – 75% of elements
• Metals demonstrate similar (but NOT identical) physical and chemical properties
Non-metals• 15% of elements
• Non-metals demonstrate properties that are the opposite of metals
Metalloids:• Elements on the staircase – 6% of elements • Exhibit properties between metal and non-metals.
Property Metal Nonmetal Metalloid
Lustre
Malleable
Ductile
State (Rm Tp)
Conduct heat
Conduct electricity
(*) – there are exceptions to these properties
shiny
solid*
dull shiny*
solid / gas* solid
semi
*
*
*
Physical change• Involves a change in shape or a change in state
of a substance• No evidence of a new material forming
H
H
O
H
H
O
H
H
O
Anything that changes what it “looks like” NOT “what it is”
Chemical change• A new substance with new properties is
formed – a chemical reaction has happened!
Evidence of a chemical reaction (and chemical change):
1. A change in colour
2. A change in smell
3. Fizzing or bubbling (new gas being made)
Testing for Gases
Oxygen• flame re-ignites
or glows brighter
Hydrogen• gas explodes
with a “pop”
4. A new solid forms from a mixture of liquids or the mixture goes cloudy
• This new solid is called a precipitate
5. A change in energy
“Energy” could be light, heat, sound – think of the most obvious change in energy reaction – an EXPLOSION!
Chemical change
Chemical properties
Chemical Reaction
Physical change
Physical properties
NO Reaction
Test the material
State or
shape
• Δ colour• Δ smell• Δ energy• Gas bubbles• Precipitate
New substance with
new properties
Same substance with
same properties
CAN YOU ANSWER THESE QUESTIONS?
S1-2-07What properties classify elements as metals, nonmetals or metalloids?
S1-2-12How do you identify physical or chemical change and if a chemical reaction has taken place?
Vocabulary & PeopleState/Phase Melting Point Boiling Point
Lustre Malleability Ductility
Solubility Conductivity Combustion
Corrosion Oxidation Hydration
Metalloids Precipitate