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Introduction to Matter
Think…Think…Think
• What is “stuff” made of?
• What are the smallest bits of things?
• If more than one kind of part makes up a
thing, what are those parts?
Ancient cultures
(Alchemists)
Think & Discuss:
Ancient cultures
- wet when you cut it so it must
have water
- grows from the ground so it has
earth
-makes smoke when it is burned
so it must have air
-can burn so it must contain fire
• Think like an ancient
person.
• Potato
• Think like an ancient
person.
• Silver
• Think like an ancient
person.
• Feather
Limitations to the four elements.
• Developed better systems to help classify matter.
• There are more than just 4 elements.
• Look at the Periodic Table
Classifying Matter
Matter
Pure Substances
Mixtures
Homogeneous
Elements
Compounds
milk,
Gatorade
Fe, O
H2O, CO2
Heterogeneous
Cookie dough
ice cream,
muddy water
MATTER
• Matter: anything that has mass and takes up space
– Mass – the amount of matter in something
– Volume – the amount of space something occupies
Made up of different kinds of atoms
Includes all things that can be seen, tasted, smelled, or touched
• Which of the following is matter?
–
–
–
–
–
A car?
A box?
You?
Heat?
Fire?
Examples of Matter
•
•
•
•
Cookies
Oxygen
You
Water
What is not matter?
-Heat
-Energy
-Light
States of Matter
• Matter can be in a solid, liquid, gas, plasma or BoseEinstein condensates (BEC) state.
www.chem4kids.com/files/matter_states.html
https://www.youtube.com/watch?v=Sri3ItB8JvA
States of Matter
• Four states: https://www.youtube.com/watch?v=88tK5c0wgH4
Bill Nye: https://www.schooltube.com/video/ea7dae4437c240958f92/Bill%20Nye%20The%20Science%20Guy%20Phases%20of%20Matter
In science, anything that has mass and takes up
space is called matter
Everything in the universe is made of matter
A really loooooong time ago, the Greeks
concluded that matter could be broken down
into particles too small to be seen.
They called these particles atoms
So, what’s an atom?
An atom is the smallest piece that matter can be
broken down into
Okay, but I’ve never seen an atom . . .
Where are they?
Atoms are EVERYWHERE!!
plants
hair
desks
boogers
CDs
Atoms are in . . .
chocolate
cheese
hot dogs
dirt
air
cars
http://htwins.net/scale2/
and even underwear
Pop Quiz Question #1
What are the four main states of matter?
A.
B.
C.
D.
solid, water, freezing, boiling
Water, ice, air, steam
Solid, liquid, gas, plasma
earth, rain, air, fire
What is a property?
• Property: a
characteristic of
a substance that
can be observed
Physical versus Chemical
Properties
The study of matter
Physical Properties
Physical property: a property that can be observed
without changing the identity of the substance.
Examples of physical
properties:
• luster
• malleability: the
ability to be hammered
into a thin sheet
• ductility: the ability
to be stretched into a
wire
• melting point
• boiling point
• density
• solubility
• specific heat
Examples of Physical Properties
• Luster: shininess
• Malleability: the ability to
be hammered into a thin
sheet
• Ductility: the ability to be
stretched into a wire
Physical Properties
• Melting point: the temperature at
which a substance changes from a
solid to a liquid at a given pressure
water = 0oC
• Boiling point: the temperature at
which a substance changes from a
liquid to a gas at a given pressure
water = 100oC
Special Physical Properties
• Solubility: amount of a substance that can be
dissolved in a given amount of solvent
• Specific heat: amount of heat required to change a
unit mass of a substance by one degree in
temperature.
• Density: the amount of mass per unit of volume
Density
• Density is the amount of mass per
unit of volume.
• Density can be used to identify a
substance.
• The density of water is 1.0g/mL
Density Calculations
• Formula:
D = m/V = g/mL = g/cm3
Density Examples
#1: A cube has a mass of 3.0 g and
occupies a volume of 6.0 ml. Would
this object float or sink in water?
Mass = 3.0 g
Volume = 6.0 mL
D = 3g/6 mL= 0.5 g/mL
– This object would float in water because
its density is less than water (1.0 g/mL).
More Density Calculations
#2: A liquid has a mass of 25.0 g and a
volume of 10.0 mL. Use the table below
to identify the substance.
M=25.0 g
V=10.0 mL
D = 25 g/10 mL
D= 2.5 g/mL
The substance is potassium.
Substance
Density (g/mL)
Mercury
13.6
Water
1.00
Ethanol
0.81
Potassium
2.5 g/ml
Chemical Properties
• Chemical property: a property that
can only be observed by changing the
identity of the substance
Examples of chemical properties:
•flammability
•ability to rust
•ability to tarnish
•reactivity with vinegar
Compounds, Mixtures, Solutions
and Reactions
Classifying Matter
Matter
Pure Substances
Mixtures
Homogeneous
Elements
Compounds
milk,
Gatorade
Fe, O
H2O, CO2
Heterogeneous
Cookie dough
ice cream,
muddy water
What is a Pure Substance?
• A pure substance is a classification of matter
that includes both elements and compounds
• Pure substances cannot be separated by physical
means such as distillation, filtration, or
chromatography
Elements
• We will study elements in depth later, but
be sure to know…
− An element is made of one kind of atom
− Found on the periodic table
What Is A Compound?
• A compound is a pure substance that is created by
2 or more elements chemically reacting and
joining together
– Ex: NaCl, H2O, CO2, NH3, NaHCO3, and C6H12O6
• Notice that elements combine in many ways to
make compounds
– Ex: H2O, H2O2, CO, and CO2
Why Do Compounds Form?
• Compounds form to allow elements to become
more stable
– Na is flammable when it comes in contact with H2O,
and Cl2 is a toxic gas
– NaCl is a very stable compound that is neither
flammable nor toxic (in normal quantities)
• Compounds that are extremely unstable will break
down to form the more stable elements
How Do Compounds Form?
• Compounds form by the interaction between
the nuclei and valence electrons of 2 or more
elements.
What Do Compounds Have To Do With My Life?
• Compounds are the substances that make up
ALL living and non-living things
• Examples: Where would you be without:
–
–
–
–
H2O—water
NaCl—table salt
C3H8O—rubbing alcohol
C55H98O6—an example of an
unsaturated fat
Classifying Matter
Matter
Pure Substances
Mixtures
Homogeneous
Elements
Compounds
milk,
Gatorade
Fe, O
H2O, CO2
Heterogeneous
Cookie dough
ice cream,
muddy water
What Is A Mixture?
• A mixture is the physical combination of 2 or
more substances
• A mixture is not chemically combined
• Mixtures can be separated by physical means
such as filtration, distillation, and
chromatography
• Mixtures can be divided into 2 groups
– Homogenous mixtures
– Heterogeneous mixtures
How Do Mixtures Form?
• Mixtures form by physically
“junking” 2 or more substances
together
• Remember no chemical change
is occurring
• The formation of a mixture is not
a result of lowering energy
What Is a Homogenous Mixture?
• A homogeneous mixture is a mixture that is evenly
distributed
• commonly called solutions
– Solution = Solute + Solvent
• Solute: “stuff” being dissolved
• Solvent: “stuff” doing the dissolving
• The solvent is present in greater quantity
• The solute is present in the lesser quantity
– Ex: Salt water: Salt=solute, Water=solvent
What Is a Heterogeneous
Mixture?
• A heterogeneous mixture is a mixture that is
unevenly distributed.
• Examples:
– Cookie dough ice cream: The chunks of dough are not
evenly distributed throughout the ice cream
– Chex Mix: You may find a different number of pretzels
or Chex cereal in each handful; therefore, the mixture is
unevenly distributed
How Are Mixtures Important To My Life?
• We encounter mixtures everywhere in
our lives
• Where would you be without:
– Ice cream
– Kool-aid
– Shampoo
– Soap
– Milk
– Orange juice
Pop Quiz Question #1
• Place an S beside each solution
and an M beside each mixture
_____
seawater
S
S
_____
steel
M
_____
salad
S
_____
air
M
_____
handful of skittles
Changes in Matter
Physical Change Examples
• Physical change: a change that
occurs that does not alter the
identity of the substance
–
–
–
–
Melting ice
Freezing Kool-aid
Tearing paper
Boiling water
• An indicator is something that produces an
observable physical change but still retains its
original form.
Some of these changes may include the
appearance or disappearance of a color.
Chemical Change Examples
• Chemical change: a change that occurs
causing the identity of the substance to be
changed.
– Burning paper
– Digesting food
– Electrolysis of water
• A chemical change is called a chemical reaction
• Cannot be undone (not reversible)
Chemical Changes Cont’d
• Indicators of a chemical change:
•
•
•
•
•
Production of light
Production of heat
Production of a gas
Color change
Formation of a precipitate
*Precipitate: an insoluble substance that is produced as result of a
chemical reaction
Is it Physical or Chemical?
Change
Melting cheese
Burning wood
Milk souring
Shredding paper
Bicycle rusting
Physical
Chemical
How Can We Change Matter Into New Substances?
• Chemical reaction (also known as a chemical
change) is a change in a substance or substances
that results in a totally new substance
– Ex: 2H2(g) + O2(g)  2H2O(g)
Notice that the reactants (the substances you start with)
combine to form a new substance (the product)
Why Do Chemical Reactions Occur?
• Chemical reactions occur to produce a more
stable product than the existing reactants
– Ex: 2Na(s) + Cl2(g)  2NaCl(s)
*The sodium is highly unstable and the chlorine
gas is somewhat unstable. The resulting
Sodium Chloride is VERY stable.
**It is important to understand that the products
have totally different properties than the
reactants
Where Does The Matter Go?
• It is important to understand that when matter
undergoes a chemical reaction (a chemical change) it
does not disappear or appear
– The atoms are rearranged and form new bonds, but no
matter is lost nor gained
• This is called the Law of Conservation of Matter
What Kind of Chemical Reactions Do I Experience?
• The acidic milk and basic baking soda that
produce CO2 gas when a cake bakes
• Paper burning to produce ashes, CO2, and
H2O vapor
• Hydrogen peroxide decomposing to
produce water and oxygen gas
Exothermic Reactions
• A reaction in which
energy is released
• Often produces an
increase in
temperature
• Reactants =
Products + Energy
Exothermic Examples
• Glow sticks- work by a chemical reaction
that releases energy as light
• Fireflies- light up by a reaction that takes
place between oxygen and a chemical called
luciferin
Endothermic Reactions
• A reaction in which energy is absorbed
• Often produces a decrease in
temperature
• Reactants + Energy = Products
Endothermic Examples
• Instant cold pack
• Photosynthesis
• Baking a cake- The cake batter will not
bake unless it absorbs energy
Simple Chemical Reactions
• Explain 3 chemical reactions on your paper
• Bill Nye – Simple Chemical Reactions
http://www.youtube.com/watch?v=PlwuxpMh8nk&safe=active