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