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�How can matter classified?
�Why are carbon and copper classified as elements?
�How are elements related to compounds?
�What is the difference between a pure substance and a mixture?
Atoms Video
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�What is matter?
�How can matter be classified?
�Chemistry- study of matter and how it changes�Helps you recognize how differences in material properties relate to what the materials are made of
WHAT IS MATTER
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WHAT IS MATTER
�Matter - Anything which has mass and takes up space.�If you can touch it, it is certainly matter
�Ex: air, animals, rocks, plants, water, etc
�Two types of matter-�Substance- Pure
�Mixture- more than one substanceWhat are two examples not classified
as matter? Light and Sound
�Sound
�Air
�Electricity
�Fire
�Computers
�X-Rays
�Books
�Pencils
�Light
�Magnetism
�Water
�Wood
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The fundamental building blocks of
matter are atoms and molecules.
ATOM MOLECULESmallest unit of
an element that
retains the
properties of that
element.
When two or
atoms bond
together by
covalent bonds.
More than 100 different types of atoms. Combine in different ways to make up anything that you can think of.
WHAT IS MATTER?
� There are two kinds of substances:� Elements
� Compounds
TWO TYPES OF SUBSTANCES
Carbon atoms
Gold atomsCopper atoms
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A pure substance made of only one kind of atom.
ELEMENTS
Elements are found on the Periodic Table of Elements
116 elements have been identified
• 83 elements occur naturally on Earth: gold, aluminum, lead, oxygen, carbon
• 33 elements have been created by
scientist: technecium, amerecium, seaborgium
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2. COMPOUNDS
�Compound- substance made of atoms of more than one element bound together�Atoms stick together to make molecules
�All molecules of a compound are the same
�Compounds behave completely differently from the elements that make them
TWO TYPES OF SUBSTANCES
Why is water a compound?
Two DIFFERENT types of atoms.
Compounds can only be separated by
chemical means into their pure components
(elements).
Water (H2O)
Sucrose (C12H22O11)
Ammonia (NH3)
Animation
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� Chemical symbols & # indicating atoms contained in basic unit of substance
� # of atoms of each element in basic unit written after element’s symbol as subscript
� No subscript is used if only 1 atom of an element is present
� # placed in front of formula show # of molecules
COMPOUNDS
H2O
2 Hydrogen atoms1 Oxygen atom
C12H22O11
12 Carbon atoms
22 Hydrogen atoms
11 Oxygen atoms
�3C16H10N2O2 (Indigo)
�5CO2
�SO2
�2HCl
�6C12H22O11 (Table sugar)
�4C6H12O6 (Glucose)
�12O2
�7NH3 (Ammonia)
�O3 (Ozone)
�55H2O
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PURE SUBSTANCES
�A sample of matter that has definite chemical and physical properties.• Every part of a given substance has the same properties
because a pure substance is a fixed, uniform composition.
• Examples: table salt and sugar
�Elements and compounds are pure substances, but mixtures are not.
TWO TYPES OF SUBSTANCES
�Carbon
�Proton
�Aluminum
�Water
�Neutron
�Sugar
�Electron
�Salt
�Iron
�Glass
�Copper
Element
Element
Element
Element
Compound
Compound
Compound
Compound
Atom
Atom
Atom
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MIXTURES
�Matter that consists of two or more substances mixed together.
�NOT chemically combined�Substances in mixture KEEP their chemical and physical properties
�Can be in any proportion
� Examples: Grape juice, air, fruit salad
•The substances are not bonded together. •Nothing new is created. It is the just the same substances mixed together.
Heterogeneous
�Different from place to place
� Parts are noticeably different
�Not evenly mixed� Ex. Sand, gravel, mixed nuts
� The same throughout�Difficult to distinguish one substance from another
� Evenly mixed�Also called solution� Ex. Kool-aid, sea water, air
MIXTURES
Homogeneous
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Separated by
chemical methods
Homogeneous mixture or Heterogeneous mixture
Heterogeneous Homogeneous
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Homogeneous mixture or Heterogeneous mixture
HeterogeneousHomogeneous
88% copper and 12% tin
Miscible-�Liquids that do dissolve in each other
�Homogeneous
�Gasoline
�Liquids that don’t dissolve in each other
�Heterogeneous
�Oil and water
LIQUID MIXTURES
Immiscible-
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SECTION 2: PROPERTIES
OF MATTER
�Why are color, volume and density classified as physical properties?
�Why are flammability and reactivity classified as chemical properties?
� In any physical or chemical change, matter is neither created nor destroyed
� Matter can be changed from one form to another.
Copyright © 2010 Ryan P. Murphy
What is the Law of Conservation of Matter?
Describe what happens to the wood when we
burn it?
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�Allow us to identify substances
�Allow us to separate substances
�Determine uses
�Two type of properties:
�1. Physical
�2. Chemical
PROPERTIES
PHYSICAL PROPERTIES
�A physical property can be observed or measured without changing the composition of the substance.
•Help identify substances.
•Can be observed or measured. • (Example: Melting Point and Boiling Point)
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Examples:• Shape, color, odor,
texture,
• Melting point (S to L),
boiling point (L to G),
• Strength, hardness,
conductivity,
magnetism, heat
• Density
PHYSICAL PROPERTIES
Durable: able to withstand damage or wear.Flexible: capable of bending easily without breaking
Physical Properties determine uses!
What would happen if you poured a hot drink into a metal cup?
PHYSICAL PROPERTIES
�Examples:
� Aluminum is used in foil because it is light weight and yet durable and flexible.
� Steel is used in cars because it is strong and provides structure.
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DENSITY
•Density is the mass per unit volume of a substance.
•Tells us how light or heavy something is.
PHYSICAL PROPERTIES
Which is denser?
Why?
Sentence:
�A lead brick is heavier than a sponge of the same size because lead is denser than sponge.
� Seawater is denser than freshwater because it contains more dissolved salts ☺☺☺☺
Density
Write a sentence comparing two objects similar
to the sentences above.
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Why the difference in volume even though their weight is the same?
Tightness of the composition of
substances in object
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� Divide the mass of the object by the volume of the object
Density = Mass
Volume
SI units
�Density = g/mL or g/cm3
�Mass = g
�Volume = mL or cm3
�Water has a density of 1 g/mL
M
D V
1. A small block of wood has a volume of 25 cm3
and a mass of 20 grams. What is the density of the block?
Density = mass
volume
D =?
M = 20 grams
V = 25 cm3
Density = 20g
25cm3
Density = 0.8 g/cm3
2. A piece of tin has a mass of 16.52 g and a volume of 2.26 cm3? What is the density of tin?
D =?
M = 16.52 grams
V = 2.26 cm3
Density = mass
volume
Density = 16.52 g
2.26 cm3
Density = 7.31 g/cm3
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3. A man has bottle completely filled with 163 g of a slimy, green liquid and a density of 3.26 g/cm3. What is the volume of the bottle?
4. A piece of metal has a density of 11.3 g/cm3
and a volume of 6.7 cm3. What is the mass of this piece of metal?
D= 3.26 g/cm3
M= 163 g
V= ?
Volume = Mass
Density
Volume =163 g
3.26 g/cm3
Volume=50.0 cm3
D= 11.3 g/cm3
M= ?
V= 6.7 cm3
Mass = Density x Volume Mass= 11.3 g/cm3 x 6.7 cm3
Mass= 76 g
Wood Water Iron
1 cm3 1 cm3 1 cm3
If you take the same volume of different
substances, then they will weigh different amounts.
0.50 g 1.00 g
8.00 g
Q) Which has the greatest mass and therefore the most dense?
IRON
DENSITY IS DIFFERENT FROM
WEIGHT
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� 1.0 g/mL
�By comparing densities!
� Density is useful because it can be used to identify a substance.
� For example, aluminum always has a density of 2.55 g/ml.
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�Way substance reacts with others to form new substances with different properties
� How it changes:
� By combining with other substances
� Or breaking apart
� Examples:� Sodium reacts easily with other elements.
� Gold does not like to react and is usually found alone.
� Argon does not react and is the gas that is in light bulbs.
� Iron will rust, carbon is flammable.
CHEMICAL PROPERTIES
Na + Cl =>
�Reactivity is the capacity of a substance to combine with another substance.
�Flammability, rust
�Flammability is the ability to burn.� If you burn anything, you change the chemical composition of that substance
and you cannot turn it back into what you started with.
CHEMICAL PROPERTIES
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P r o p e r t i e s o f M a t t e r
Physical Chemical
Can be observed or measured
without changing the identity of the
substance.
Examples of Property
Substance interacts with other
substances to produce new
substances.
Reactivity
Flammability
Rust
Cooking
Burning
color
odor
taste
hardness
density
melting points
freezing points
Examples of Property
Comparison of Physical and Chemical Properties
Substance Wood Iron Red dye
Physical
Property
Chemical
Property
Has a
grainy
texture
Bends
without
breaking
Has red
color
Is flammableReacts with
oxygen to
form rust
Reacts
with
bleach,
loses color
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�Why is getting a haircut an example of a physical change?
�Why is baking bread an example of a chemical change?
�How can mixture and compounds be broken down?
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Changes of Matter
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1. Physical Change: occurs without a change in composition, but when the physical form or properties are changed.�The atoms are not changed or rearranged.
Physical Changes
Examples:• Grinding peanuts into
peanut butter.• Pounding a gold
nugget into a ring.• Dissolving, cutting,
crushing, etc.• Melting ice cubes or
gold.• Any phase changes
(solid, liquid, gas)
Physical Changes
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Write some examples.
1. A change in physical properties, but there is no change in the substances' chemical properties or chemical composition.
2. No new substance is formed.
3. It is a change from one phase of matter to another.
4. Examples include: grinding, cutting, melting, and boiling. These types of changes do not change the identity of the substance.
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2. Chemical Change: happens when one or more substances are changed into entirely new substances that have different properties.
�The substances after the change are different from the substances at the beginning.
Chemical Changes
Chemical ChangesClues often suggest that a chemical change has
happened.
•A change in odor
•Color changes
•Fizzing or foaming
from gas being given
off
•Production of sound,
heat, light, or odor. CO2 being formed
What color was the Statue of Liberty originally? Why
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Examples:• When you burn anything.• When a battery dies, the chemicals inside have changed.• When you breathe in oxygen and air, but breathe out
carbon dioxide.• When you mix vinegar and baking soda and get a gas and
a saltwater.• Leaves changing color in the fall.
Chemical Changes
C₆H₁₂O₆ + 6O₂→ 6CO₂ + 6H₂O + energy
Ch
em
ical
Ch
an
ges
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Because new substances are formed in a
chemical change, they cannot be reversed by
physical changes!
Chemical Changes
Practice Problems
Indicate if each of the following is a physical
or a chemical change:
a) Tearing a sheet of paper
b) Burning a log
c) Melting a piece of wax
d) Melted butter solidifies in the refrigerator
e) The rusting of iron
f) The dissolving of sugar in water
Answers
a) Physical
b) Chemical
c) Physical
d) Physical
e) Chemical
f) Physical
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Mixtures
�Separated by physical changes• Physical removal of parts
(pizza toppings)• Evaporation (seawater)• Boiling or distillation • Centrifugation or spinning
rapidly (blood)
• Each of the individual substances retains its own individual properties
Compounds
�Must be broken down by chemical changes.�Heating�Using electric current
(breaking up table salt into sodium and chloride)
�Chemical reactions (breaking compounds into simpler substances, which can be broken down into elements)
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Breaking Down Mixtures &
Compounds
METHODS OF SEPARATING MIXTURES INTO THEIR INDIVIDUAL COMPONENTS:
Filtration
Evaporation
Decanting
Centrifuge Paper
Chromatography
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