introduction to matter - weebly...3 + hc 2 h 3 o 2- nac 2 h 3 o 2 + h 2 co 3 (baking soda) (vinegar...
TRANSCRIPT
Introduction to Matter
Matter
• Anything that has mass and takes up space
– Solids
– Liquids
– Gases
Weight • A measure of the gravitational force exerted
on an object
• What is the difference between weight and mass?
• How do you measure weight?
– SPRING SCALES!
Mass
• The amount of matter in an object
• How do you measure mass?
– Balances!
• Dual Tray Balance
• Triple Beam Balance
Mass: The Measure of Inertia
• How hard would it be to push a large bus?
• How hard would it be to push a grocery cart?
Inertia
• The tendency of an object to resist a change in motion
• If an object is still, it tends to stay still
• If an object is moving, it tends to keep moving
How do we convert between weight and mass?
P. 8
Volume
• The amount of space taken up by an object
• How calculate for a rectangular prism?
Volume = length x height x width
• Check bell work…
Density
• Ratio of mass to volume
• A dense object has a large mass compared to a small volume
Physical Properties • What are some examples?
Physical properties are descriptions of characteristics
of objects that do not involve chemical change
Physical Properties
• Objects have physical properties
• Physical properties are descriptions of characteristics of objects that do not involve chemical change
• Unknown substances can be identified by their physical properties
Physical Properties
• Thermal
Conductivity
• State
• Density
• Ductility
• Malleability
• Color
• Odor
• Conductivity
• Solubility
• Hardness
• Luster
• Attracted to
magnet See page 11
Physical Changes
• A change in matter that does not result in chemical changes
• substance’s identity stays the same
• Examples:
– Change in state (Dissolving, Melting, freezing)
– Change in shape or volume
Chemical Property
• A description of a substance’s ability to take part in chemical reactions
Examples of Chemical Properties • Flammability
– The ability to catch on fire
• Reactivity – The ability of two or more substances to form a new
substance • Oxidation : A result of the ability of a substance to react
with oxygen
• Toxicity – The ability to be poisonous
• Sensitivity to Light
• Radioactivity
Chemical Changes • When one or more substances are changed into entirely NEW substances with different
properties
• Chemical Changes change the identity & composition of the matter involved – Physical changes do NOT
• Reactants are changed into products
Comparing Physical and Chemical Properties
• A physical property can be observed without changing the identity of the substance
• To observe a chemical property, the substance must undergo a chemical change
Matter and Chemical Change • Chemical Changes change the identity of the
matter involved
• Reactants are changed into products
What are SIGNS of a Chemical Change?
• Changes in color
• Changes in odor
• Changes in temperature (heat or cold)
• Bubbling, fizzing or foaming
• Sound or light given off
What Happens During a Chemical Change?
• Changes in physical properties
– What is seen, heard, felt, smelled?
• Changes in temperature
– Is heat energy absorbed or released?
• New substances form
– Did reactants create new products?
Density • What is happening here, in terms of
“particles of matter?”
Physical vs. Chemical Change
• Can the change be reversed?
– Physical changes can be easily reversed
• Examples?
– Chemical changes cannot be easily reversed
• Examples?
• Can they NEVER be reversed?
Comparing Physical and Chemical properties
• How can you tell the difference between a physical or a chemical property?
Physical vs. Chemical Change • Composition is the type of matter that makes up an
object
• Did the composition change?
• Physical changes do not change the composition of a substance
• Chemical changes do change the composition
Comparing Physical and Chemical Properties
• A physical property can be observed without changing the identity of the substance
• To observe a chemical property, the substance must undergo a chemical change
Examples of Chemical Changes
Are Examples of Chemical Changes Uncommon?
NO!
Characteristic Properties • The properties that are most useful in identifying a
substance
• Do not depend on sample size or amount
• Can be physical properties as well as chemical properties
• Examples: – Density, solubility (physical)
– Flammability, reactivity (chemical)
Endothermic vs. Exothermic
Energy IN
Energy OUT
Baking Soda & Vinegar Reactions
NaHCO3 + HC2H3O2 - NaC2H3O2 + H2CO3
(Baking Soda) (Vinegar or Acetic Acid) (Sodium Acetate) (Carbonic Acid)
“REACTANTS” “PRODUCTS”
What would be evidence of energy being transferred during reaction?
Baking Soda & Vinegar Reactions
Called a “Double Replacement” reaction
Different elements in two different compounds (reactants) replace each other
NaHCO3 + HC2H3O2 - NaC2H3O2 + H2CO3
(Baking Soda) (Vinegar or Acetic Acid) (Sodium Acetate) (Carbonic Acid)
Carbonic Acid immediately breaks down into H2O (water) and CO2 (Carbon Dioxide)
“REACTANTS” “PRODUCTS”
Tree Maps!
Physical
Properties 1. X
2. X
3. X
4. X
Changes 1. X
2. X
3. X
4. X
Chemical
Properties 1. X
2. X
3. X
4. X
Changes 1. X
2. X
3. X
4. X
Physical
Properties 1. Thermal Conductivity
2. State
3. Density
4. Ductility
5. Malleability
6. Color
7. Odor
8. Conductivity
9. Solubility
10. Hardness
11. Luster
12. Attracted to magnet
Changes (examples)
1.
2.
3.
4.
5.
6.
7.
8.
Chemical
Properties 1. Flammability
2. Reactivity
3. Oxidation
4. Toxicity
5. Sensitivity to Light
6. Radioactivity
Changes (examples)
1.
2.
3.
4.
5.
6.
7.
8.
What are SIGNS of a Chemical Change?
• Changes in color
• Changes in odor
• Changes in temperature (heat or cold)
• Bubbling, fizzing or foaming
• Sound or light given off
Characteristic Properties
• The properties that are most useful in identifying a substance
• They can be physical properties as well as chemical properties
• Examples may be physical OR chemical
– Density, solubility
– Flammability, reactivity
Change in state (melting,freezing,etc.)
Change in shape
Change in volume
Dissolving
Hot Gas
Rusting (“oxidation”)
Soured Milk
A Chemical Reaction
Matter
• Anything that has mass and takes up space
– Solids
– Liquids
– Gases
Mass
• The amount of matter in an object
• How do you measure mass?
– Balances!
• Dual Tray Balance
• Triple Beam Balance
Mass: The Measure of Inertia
• How hard would it be to push a large bus?
• How hard would it be to push a grocery cart?
Inertia
• The tendency of an object to resist a change in motion
• If an object is still, it tends to stay still
• If an object is moving, it tends to keep moving
How do we convert between weight and mass?
P. 8
Volume
• The amount of space taken up by an object
• How calculate for a rectangular prism?
Volume = length x height x width
• Check bell work…
Physical Properties
• Objects have physical properties
• Physical properties are descriptions of characteristics of objects that do not involve chemical change
• Unknown substances can be identified by their physical properties
Physical Properties • What are some examples?
Physical properties are descriptions of characteristics
of objects that do not involve chemical change
Let’s Review Physical Properties
• Thermal
Conductivity
• State
• Density
• Ductility
• Malleability
• Color
• Odor
• Conductivity
• Solubility
• Hardness
• Luster
• Attracted to
magnet See page 11
Let’s Review Physical Changes
• A change in matter that does not result in chemical changes
• substance’s identity stays the same
• Examples:
– Change in state (Dissolving, Melting, freezing)
– Change in shape or volume
Density • What is happening here, in terms of
“particles of matter?”
Density
• Ratio of mass to volume
• A dense object has a large mass compared to a small volume
Meniscus