Transcript of matter

Page 42
S8P1. Students will examine the scientific view of the nature of
matter.
a. Distinguish between atoms and molecules
Page 43
S8P1a.
Matter
10/12/1
2
What is matter and how can it be classified?
Matter is anything that has mass and takes
up space.
Examples: book, toy, car, paper
Non-examples: heat, light
Matter is made of tiny indivisible particles
called atoms. Atoms are the basic building
blocks of all matter.
For many years, people have wondered
what matter is made of including
Democritus, Lavoisier, Dalton, Thompson,
Rutherford and Bohr.
Page 45
Democritus thought the universe was made
of empty space and tiny bits of stuff that
were so small they could no longer be
divided into smaller pieces. He called these
pieces atoms.
Lavoisier came up with the law of
conservation of matter, which states that
matter is not created or destroyed – it only
changes forms.
wood + oxygen = ash + gases + water vapor
Dalton developed the atomic theory of
matter. He felt that matter was too small
to be seen by the human eye and that each
type of matter was made of only one kind
of atom.
Page 47
Thompson discovered that atoms were a
ball of positive charge embedded with
negatively charged particles, called
electrons.
Rutherford called the positively charged,
center part of the atom the nucleus. He
named the positively charged particles in
the nucleus, protons. He concluded that
the atom must be mostly empty space in
which electrons travel in random paths
around the nucleus.
Chadwick, a student of Rutherford’s
discovered uncharged particles in the
nucleus, called neutrons.
Page 49
Bohr found that electrons are arranged in
energy levels in an atom. The lowest
energy level is closest to the nucleus. It can
only have two electrons. Higher energy
levels are farther from the nucleus.
According to Modern Atomic Theory,
electrons move in a cloud around the
nucleus.
Atoms are very small. It would take a
million of them combined to be the size of
a pencil tip.
As tiny as atoms are, they consist of even
smaller particles – protons, neutrons and
electrons.
On page 46,neatly illustrate, color and label Rutherford’s
Model of the Atom with Chadwick’s contribution of the
neutron. When labeling, label and define the nucleus,
electrons, protons, neutrons.
On the top half of page 48, neatly illustrate, color and label
Bohr’s Model of the Atom
On the bottom half of page 48, neatly illustrate, color and
label the current model of the atom.
Page 51
The nucleus is the small dense, positively
charged center of an atom. It contains the
most of the atom’s mass. The nucleus
contains protons and neutrons.
Protons are positively charged particles
located inside the nucleus.
Neutrons are neutrally charged particles
located inside the nucleus.
Electrons are negatively charged particles
found in electron clouds outside the
nucleus.
On page 50
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Page 51 & 53
There are two kinds of pure substances:
elements and compounds.
An element is matter made up of only one
kind of atom. There are over 100 known
elements. About 90 of them are found
naturally on Earth and the other 20+ are
synthetic (man-made).
All known elements are arranged in a chart
called the periodic table of elements. Each
element on the chart has a chemical symbol
with one to three letters.
The periodic table is arranged in rows called
periods and columns called groups or
families. There are 7 periods and 18 groups.
Page 53
Elements in the same group share similar
properties.
Each element has an atomic number and an
atomic mass.
The atomic mass is the average of all of the
isotopes of an element.
The atomic number is ALWAYS the number of
protons. It is also the number of electrons in a
neutral atom. To determine the number of
neutrons, you must subtract the atomic
number from the atomic mass.
For example, Copper has an atomic number of
29 and an atomic mass of 63. It has 29
protons , 29 electrons and 34 neutrons.
On page 52
Look at the periodic table and identify the group name of the
following elements:
1. Lithium
2. Xenon
3. Gold
4. Beryllium
Page 55
Sometimes the atomic mass of elements
can change. For example Hydrogen
sometimes has an atomic number of 1, 2 or
3. This is because the number of neutrons
may vary.
Isotopes are atoms of the same element
that have a different number of neutrons.
When referring to an isotope, you state the
element name followed by its atomic mass.
For example:
Hydrogen-1 or Hydrogen-2 or Hydrogen-3
Page 59
Matter
S8P1a., S8P1f.,
S8P1d
How can matter be classified?
10/31/1
2
All forms of matter can be classified into
two groups: pure substances and mixtures.
A pure substance is one having a
homogeneous composition. There are
two types of pure substances: elements
and compounds.
An element is matter that is made of only
one kind of atom. A compound is matter
that is formed when two or more elements
join (bond) chemically. They cannot be
broken apart.
On page 58
Identify whether each of the following are elements or
compounds in the table below.
H
Fe2S
H20
OH
Ca
Na
CH4
Element
NaCl
NaOH
CO2
CO
Compounds
Co
SiO2
Page 61
A molecule is the smallest unit of a
compound that has all the properties of the
compound. The makeup of a molecule is
shown in a chemical formula. A chemical
formula uses chemical symbols and
subscripts to identify the number and types
of atoms of each element that make up a
compound.
A subscript is a small number written to the
right and slightly below a chemical symbol
to tell the number of atoms of that element
is in the substance.
The chemical formula for water is H20.
This means one molecule of water has 2
Hydrogen atoms and 1 Oxygen atom.
On page 60
Determine the number of atoms of each element present in
each of the following compounds.
1. CO
2. CO2
3. H2O2
4. NaCl
5. NaOH
6. C12H22O11
7. FeS2
8. Fe2O3
9. C2O
10.Na2O
11.CH4
Page 63
Elements can combine in different ways to
form either compounds or mixtures. A mixture
forms when two or more substances combine
without joining chemically. They are not
bonded together.
Because they are not bonded chemically, the
parts of a mixture retain their own individual
identities and properties and can be separated.
A mixture that is unevenly mixed is called a
heterogeneous mixture. Ex. Trailmix. A mixture
that is mixed evenly is called a homogeneous
mixture. Ex. Kool-Aid
Summary: EQ- How can matter be classified?
On page 62
Identify whether each of the following are heterogeneous or
homogeneous mixtures in the table below.
Vegetable soup
Chex Mix
coffee
cake batter
chocolate chip cookie
milk
salt water
pizza
spaghetti & meatballs
cereal in milk
taco salad
Heterogeneous Mixture
Homogeneous Mixture
Page 65
S8P1a., S8P1f.,
S8P1d
States of Matter
11/2/12
Water can be found in solid, liquid and gas forms, how does
that happen?
A state of matter is the physical form in
which matter exists. There are four states
(phases) of matter : solid, liquid, gas and
plasma. Matter often changes state when
heat is added or taken away.
A solid is a substance with a definite shape
and a definite volume. The particles in a
solid are packed closely together and
maintain a rigid form without a container.
They vibrate slowly against one another.
Page 67
A liquid is a substance with a definite volume,
but not a definite shape. The particles in a liquid
move faster and freely past one another, but
are still close to one another. Liquids take the
shape of the container they are in.
A gas is a substance that does not have a
definite shape or a definite volume. Gas
particles move very fast and bounce off of one
another. Gases fill the container they are in.
Page 69
The transformation of matter from one state to
another is called a phase transition. Phase
transitions occur at precise points when the
energy of motion in the atom is too much or too
little for the atom to remain at that state.
Phase Transition
Description
Melting (add heat)
Solid to Liquid
Evaporation (heat added)
Liquid to Gas
Sublimation (heat added)
Solid to Gas (skipping Liquid)
Condensation (heat removed)
Gas to Liquid
Freezing (heat removed)
Liquid to Solid
Deposition (heat removed)
Gas to Solid (skipping Liquid)
Summary: EQ-Water can be found in solid, liquid and gas forms. How does that
happen?
On page 64
Identify whether each of the following are solids, liquids or
gases in the table below.
Milk toy car
helium
hydrogen
steam
sugar
salt
pepsi
Solid
Liquid
water
ice
oxygen
Gas
On page 66
The freezing point and melting point are the same temperature.
On page 68
The following processes are phase transitions. Make the table
below and identify what they are.
Phase Transition
Water droplets coat your cold
soda can on a hot day.
A cloud releases rain.
Solid dry ice steams in air.
Glaciers floating in the ocean
are shrinking.
Morning dew disappears from
the grass by midday.
A cloud releases snow.
Page 71
S8CS1, S8CS2, S8CS5,
Scientific Method
S8CS9 and S8P3
11/27/12
How does the design and construction of a bridge affect its
durability and ability to withstand weight?
Bridge #
1
2
3
4
5
6
7
8
9
Design / Description
Maximum
Weight
Failure Description
On page 70 Popsicle Bridge Lab Write-Up
Question:
Hypothesis:
Procedure:
Materials:
Observations:
Analysis:
Results:
Conclusion:
Leave page 73 blank
Page 75
S8P1d.
Properties of Matter
12/3/12
What are the various properties of matter and how can I distinguish
between physical and chemical properties of matter?
A property is a characteristic of matter.
A physical property is a characteristic that can be
observed or measured without changing the
identity of a substance.
Examples: density (mass/volume), electrical
conductivity, hardness, pH, state of matter and
luster
A chemical property is a characteristic that
describes how a substance will interact with other
substances during a chemical reaction.
Examples: reactivity, the ability to burn and rust
Summary: What are the various properties of matter and how can I distinguish
between physical and chemical properties of matter?
page 74
Create a two-column table and classify each of the terms
below as either a physical property or a chemical property.
reacts with base to form water
Boiling point
density
Taste
reacts with an acid
color
flammability
melting point
luster reacts to oxygen
solubility hardness odor reacts with water to form gas
Physical Property
Chemical Property
Page 77
S8P1.d & S8P1.e
Changes in Matter
12/3/12
What types of changes can matter undergo? What happens to
matter when it undergoes changes?
Matter can change. The types of changes matter
undergoes are classified into two groups: physical
changes and chemical changes.
A physical change alters the physical properties of
a substance without changing the identity of the
substance. Physical changes cause a change in
properties such as volume, mass, or state of
matter. Many physical changes can be reversed.
Examples: melting, evaporating, freezing, cutting
A chemical change occurs when a substance is
changed into a new substance with different
properties. During a chemical change, the identity
of a substance is changed.
Examples: burning, rusting, baking, combusting
Page 79
A chemical reaction is the process by which new
substances are formed during a chemical
change. Some signs that indicate a chemical
reaction has occurred include the forming of
gases, a change in color, the release of heat, or
the emission of light.
Another sign of a chemical reaction is the
formation of a precipitate. A precipitate is a
solid that forms from a chemical reaction that
takes place in a solution.
It is very difficult or impossible to reverse the
effects of a chemical change.
Summary: EQ - What types of changes can matter undergo? What
happens to matter when it undergoes changes?
page 76
Create a two-column table and classify each of the descriptions below as
either a physical change or a chemical change.
Iron rusts
sodium hydroxide dissolves in water
milk goes sour
a match ignites and burns
an ice cube melts to form a puddle of water
icicles form at the edge of a roof
chocolate bar melts in the sun
water is heated and changed into steam
vinegar and baking soda react
acid on limestone produces carbon dioxide gas
wood and leaves rot
a tea kettle begins to whistle
Physical Change
Chemical Change
page 78
PHYSICAL OR
YES
PHYSICAL
CHANGE
CHEMICAL CHANGE?
QUESTION: AFTER THE CHANGE
IS IT THE SAME SUBSTANCE?
EVIDENCE OF A CHEMICAL CHANGE
BUBBLING
TURNS CLOUDY
TEMPERATURE CHANGES
EXOTHERMIC – ENERGY IS EXITING - GETS HOTTER
ENDOTHERMIC – ENERGY IS ENTERING – GETS COOLER
COLOR CHANGE
CHANGE IN SMELL OR TASTE
NO
CHEMICAL
CHANGE
Page 81
S8P1g.
Conservation of Matter
12/4/12
During a change in matter, how does the amount of matter
compare before and after it changes?
The law of conservation of matter states that,
during a chemical reaction, matter cannot be
created or destroyed.
Even though the matter may change from one form
to another, the same number of atoms exist before
and after the changes take place.
Reactant – the substances there before a reaction
occurs.
Product – the substances there after the reaction
takes place.
MASS OF REACTANT = MASS OF PRODUCT
UNDERSTANDING CHEMICAL REACTIONS &
THE LAW OF CONSERVATION OF MATTER
If 25g of Potassium
is reacted with 5g of
Oxygen, how much
Potassium Oxide is
produced?
4K + O2
25g
+
5g
Reactants
2H2 + O2
A coefficient shows the
number of molecules.
2H2 means 2 hydrogen
molecules for a total of 4
hydrogen atoms.
Page 83
2K20
30g
Products
2H20
A subscript shows how
many atoms are in a
formula. In O2, the 2
means 2 atoms of
oxygen.
page 80 – Write the questions and answer each.
How many different elements are present?
N2
CaF2
CO2
NaSO3
CaCO3
SiO2
How many molecules are present?
2H2O
5Be2Br
8CO2
3NaCl
O2
MgS
How many total atoms are present?
2H2O
2Be2Br
7CO2
6NaCl
4O2
2MgS
Using this reaction, answer the following questions.
Li2O + MgCl2  2LiCl + MgO
Name the first reactant.
Circle the second reactant.
Underline the first product.
Name the second product.
How many Mg atoms are on the reactant side? the product side?
How many Chlorine atoms are on the reactant side? the product side?
page 82 – Write each chemical reaction (and question) and
determine the missing value?
If 23g of Magnesium is reacted with
Oxygen to produce 38 g of Magnesium
Oxide, how much Oxygen was used in
the reaction?
2Mg + O2  2Mg0
23g
+ ?g
2KCl + Li2O
21g
+
4g
38g
 K2O + 2LiCl
?g
+
12g
Using the numbers provided,
determine how much K2O is
produced in the reaction.