UNDERSTANDING THE NATURE OF MATTER
AND IT’S CLASSIFICATION
Historically, much of the evidence and reasoning used in developing atomic/molecular theory was
complicated and abstract. In traditional curricula too, very difficult ideas have been offered to
children before most of them had any chance of understanding.
The atomic theory of matter suggests that:
By the end of the 8th grade, students should have sufficient grasp of the general idea that a wide
variety of phenomena can be explained by alternative arrangements of vast numbers of invisibly
tiny, moving parts.
1. All matter consists of atoms.
2. All atoms of an element are identical.
3. Different elements have different atoms with a different number of protons, neutrons and
electrons.
4. The center of the atom contains the nucleus that has most of the mass of the atom. Holy Cow
batman it takes 2000 electrons to make one proton or neutron.
5. The charge of the atom is neutral because the number of protons in the nucleus equals the
number of electrons in the space outside the nucleus.
6. Electrons orbit the nucleus. When an electron moves from an outer orbit to an inner orbit, it
gives off energy (including light). When an electron moves from an inner orbit to an outer orbit,
it absorbs energy.
7. The packets of energy electrons absorb or give off are called photons.
8. The atomic number is the number or protons.
9. A stable electron arrangement is an atom that has all the electrons at the lowest energy (orbital)
levels.
10. The atomic mass is the number of protons and neutrons.
11. The atomic mass is an average since the number of neutrons can vary in the atoms of one
element.
Distinguish among the types of matter (e.g. elements, compounds, mixtures).
1. ELEMENT – An element is a substance that cannot be broken down into other substances. We
need to know there are 100 elements on the periodic table.
2. ATOM – An atom is the smallest particle of an element that retains its properties of that
element.
3. COMPOUND – A compound is made of two or more elements that have been chemically
combined by sharing electrons. They are combined in definite proportions. 2 hydrogen and 1
oxygen make H20 or water.
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o COMPOUND DIAGRAM- This is hydronium not Hydrogen. Notice the three
hydrogen atoms are sharing electrons with one oxygen atom. There are 4 atoms
and the formula is H30.
o
-
This is the Lewis structure or electron dot diagram for the hydronium ion.
4. CHEMICAL BOND – A chemical bond is the force of attraction that holds atoms together by
sharing electrons.
5. LAW OF DEFINITE PROPORTIONS - says that elements in a compound always combine in the
same proportion to make the molecules that make up the compound.
6. MOLECULE – the smallest part of a compound is a molecule which is elements combined in a
definite proportion or set ration.
7. CHEMICAL FORMULA that reactant + reactant  product, is a shorthand way of showing the
elements of a molecule of a compound. 2 hydrogen + 1 oxygen  H20 or water. NOTICE
THERE ARE 3 atoms in water. 2 H and 1 O.
8. For our purposes – Elements are made of atoms, Compounds are made of molecules. Both are
pure substances.
COMPOUNDS AND MIXTURES ARE SIMILAR IN THAT THEY ARE MADE UP OF
TWO OR MORE SUBSTANCS.
1.
2.
3.
4.
5.
2
Compounds (pure substance)
Made of one kind of particle (H20
molecule, NaCl molecule, etc.).
Formed during a chemical change.
Broken down only by chemical changes.
Properties are different from its parts.
Hydrogen and Oxygen are gases that burn.
H20 is a liquid that does not burn. Na
(Sodium) and Chlorine (Cl) are poisons but
you can eat table salt (NaCl).
There is a set formula and a specific
amount of each ingredient in the
molecules making the compound.
Mixture (not a pure substance)
1. Made up of two or more molecules and
the amount can vary.
2. Not formed by chemical change.
3. Can be separated by physical changes.
4. Properties are the same as its parts. Sugar
water is sugar and water. The amount of
each can vary.
5. Does not have a definite amount of each
ingredient.
6. Heterogeneous – I can see the different
parts – salad, blood, cereal
7. Homogeneous – I can’t see the different
parts. Sugar water, salt water, Kool-Aid.
PHYSICAL AND CHEMICAL PROPERTIES.
Students should become familiar with characteristics of different states of matter—now including
gases—and transitions between them. Most important, students should see a great many examples
of reactions between substances that produce new substances very different from the reactants.
Then they can begin to absorb the rudiments of atomic/molecular theory, being helped to see that
the value of the notion of atoms lies in the explanations it provides for a wide variety of behavior of
matter.
PHYSICAL PROPERTY – A physical property is one that can be observed without changing the identity of
a substance. You can describe color, mass, shape, and volume.
CHEMICAL PROPERTY – Chemical properties describe the ability of a substance to be changed into new
substances.
PHYSICAL PROPERTY
1. Color
2. Dissolving. Same as solubility.
3. Solubility – The amount of a substance (solute) that
will dissolve into another substance (solvent).
Saturated is when no more can be absorbed or
dissolved. Depends on heat of solvent (think of hot
tea and ice tea)
4. Mass – Mass is the measure of the amount of matter
in an object.
5. The idea of gravity—up until now seen as something
happening near the earth's surface—can be
generalized to all matter everywhere in the
universe. Some demonstration, in the laboratory or
on film or videotape, of the gravitational force
between objects may be essential to break through
the intuitive notion that things just naturally fall.
6. Weight – Weight is the measure of a planet’s pull of
gravity on an object. If I take my science book to the
moon, the mass stays the same but the weight
changes and is less than on earth.
7. Volume – Volume is the amount of space an object
has. Regular objects are measured in cm3 and irregular
objects are measured in ml (milliliters) by placing them
in a graduated cylinder.
8. Density – Density is the mass of a substance contained
in a unit of volume. D=M/V. Density is measure in
g/cm3 or in g/ml.
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CHEMICAL PROPERTY (NEW
SUBSTANCE)
1. A change in color (A rotting
banana, a burning chair).
2. Combustion – The heat of
combustion is the heat of
reaction.
3. Explosiveness
4. Flammability
5. Reactivity
6. PH (acids 0 and bases 14,
remember 7 is neutral)
7. Cooking
9. Specific Gravity – is the ratio of the density of a
substance to the density of water. If the specific
gravity is less than one the object floats on water. 1
g/ml is the density of water.
10. Conductivity – The ability to carry heat or electricity.
Metals are good conductors and Nonmetals are poor
conductors but good insulators.
11. Changes in state – melting point, freezing point, boiling
point, condensation point.
12. Hardness – How difficult it is to heat or scratch a
substance.
PERIODIC TABLE OF ELEMENTS
The elements in the Periodic Table are arranged in numerical order (1, 2, 3... 100) by the number of
protons. This is known as the atomic number.
ELEMENT KEY – The element key shows at least 4 pieces of information
1. Element symbol – C is Carbon, Na is sodium, Cl is chlorine, and H is hydrogen. Notice the first
letter is capitalized.
2. The Element name.
3. The atomic number – number of protons. IT IS THE SMALLER NUMBER.
4. The atomic mass – the number of protons and neutrons. This is also called the atomic weight. IT
IS THE LARGER OF THE TWO NUMBERS.
PERIODS – When I write a horizontal sentence, I end it with a period. There are 7 periods.
FAMILIES or GROUPS – We are family, we go vertically. ELEMENTS IN A FAMILY OR GROUP HAVE
SIMILAR PROPERTIES AND ACT THE SAME AS OTHER ELEMENTS IN A FAMILY.
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METALLOID DANCE Non-metals include non-metals, metalloids, and
Nobel/inert gases.
METALS (left hand)
Shiny, hard, conduct
heat, conduct
electricity, chemically
active or reactive,
bases, ductile,
malleable.
There is only one metal
that is not a solid –
liquid mercury.
Metalloid (tushie)
Have properties that
are in between metals
and non-metals.
FUSES, Semiconductors
like the element Silicon
Si)
PHYSICAL PROPERTIES –
All solids that look
white and gray but are
not shiny. They will
conduct heat and
electricity but not as
well as metals and not
at all temperatures.
CHEMICAL PROPERTIES
– Each metalloid must
be studied individual
and all have some
properties of metals
and some of nonmetals.
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Non-metal (right hand)
Dull, brittle, good
insulators and poor
conductors of heat and
electricity, acidic, some
gases, some solids.
There is only one nonmetal that is a liquid –
liquid bromine.
Nobel/Inert Gas (pinky)
Are all gases at room
temperature. They do
not react chemically
with other elements.
They are inert
(inactive).
UNDERSTANDING CHANGES IN MATTER
CHANGES IN MATTER – analyzing physical, chemical, and nuclear changes in
matter and the factors that affect these changes.
Physical change – is a change that does not produce a new substance.
Chemical change (or chemical reaction( is any change of a substance (reactant) into one or more other
substances  product.
PHYSICAL
PHASES OF MATTER
Solid – most common state of matter one earth.
Liquid
Gas
Plasma – most common state of matter in universe
found in stars and lightning.
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Definite shape, definite volume, low energy level
(cold), strong gravity attraction.
Indefinite shape, definite volume (can’t make it
smaller).
Indefinite shape (takes the shape of entire
container), indefinite volume, high energy level
(hot), week gravity attraction.
Is a gas that has become so hot that electrons have
escaped leaving a positive nuclei (nucleus with no
electrons).
Physical Phase Changes
PHASE CHANGES ARE PHYSICAL CHANGES
Melting
Freezing
Boiling
Evaporation
Condensation
Deposition – no liquid state
Sublimation – no liquid state
CHEMICAL
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Solid to liquid - endothermic
Liquid to solid - exothermic
Liquid to gas that takes place inside the liquid and
on surface. Endothermic
Liquid to gas over time. Takes place only on the
surface of the liquid. Endothermic
Gas to liquid. Exothermic.
Gas to solid
Solid to gas. Snow disappearing from a mountain
top where the temperature is below freezing.
Energy is released (exothermic) or absorbed (endothermic) in a chemical reaction.
Law of Conservation of Mass – Matter is neither created nor destroyed, just transformed. So chemical
equations must be balanced. 2H2 + O2  2H2O. reactant + reactant  become product (plus or
minus) energy. Total matter and total energy remains the same.
NUCLEAR
Gamma rays (y) are high energy electromagnetic waves. Protection from gamma rays requires lead or
concrete.
NUCLEAR FUSION - (join) – Hydrogen nuclei fuse or join together to make helium nuclei. Nuclear The
suns energy is generated by nuclear fusion.
NUCLEAR FISSION (split) – Nuclear fission is the splitting of a nucleus into smaller fragments by
bombardment with neutrons. Controlled fission is the source of energy in nuclear power plants.
Identifying the components and properties of solutions, including acids and
bases, and factors that affect solubility.
SOLUTE, SOLVENT, SOLUTION.
Solution – the homogeneous solution produced when a solute is dissolved in a solvent.
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Solvent – the liquid that dissolves a solute. WATER
Solute – the solid that is dissolved in the solute. Sugar, water, Kool-Aid powder.
Saturated – when no more solute can be dissolved or with a paper towel no more water can be
absorbed.
Unsaturated – no solute is present.
Supersaturated – A can dissolve a lot more sugar in boiling tea and make it super saturated with sugar.
ACIDS AND BASES
Think of a number line 0 to 14 with 7 being the middle or neutral number. 0 is the A or Acid. And at
the other end B is the base. 7 is the neutral number. The farther from 7 the more acid a substance as
you go to 0 and farther from 7 the more base of a substance as you reach 14.
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Metals are bases. Non-metals are acids. Water is a neutral and is at 7 on the PH scale.
Acids have a sour taste (vinegar and lemon juice), Bases have a bitter taste and the stronger ones feel
slippery. Many household cleaning products are bases.
Water is formed and when an acid and a base combine chemically and a salt is also formed.
ANALYZING FACTORS THAT AFFECT CHEMICAL REACTIONS (E.G. TEMPERATURE
AND CATALYSTS).
Kinetic energy is the energy of motion. Kinetic molecular theory says particles in stuff (matter) are in
constant motion. The particles do not lose energy in collisions. Most reactions increase temperature
because more and more molecules have the kinetic energy to overcome the reactions activation energy.
Activation energy – Is the minimum energy required to loosen bonds in molecules to allow them to
become reactive. The energy you give a match when you strike a match on the match box.
Catalyst – A catalyst is a material that increases the rate of a chemical reaction without being changed
permanently itself.
Two ways to increase the rate of reaction
1. Increase the temperature – meaning more molecules collide per second, and these collision
occur with more energy and reach the activation level sooner. Try to start a fire on a hot day
compared to a cold day.
2. Increase the surface area of the reaction. We set twigs on fire and then the big log. We don’t
start with the big log. Sugar dissolves better in small particles.
IDENTIFYING CHARACTERISTICS OF A SYSTEM AT EQUILIBRIUM
The activation is the minimum energy needed to overcome the barrier to the formation of products.
Remember reactant + reactant (plus or minus) energy  product (plus or minus) energy.
Exothermic – the energy of the products is lower than the energy of the reactants.
Endothermic – the energy of the products is greater than the energy in the reactants.
*** Energy is not created. When you strike a match you give energy from the food you ate that is added
to the reaction.
UNDERSTAND PRINCIPLES AND CONCEPTS
RELATED TO ENERGY
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At this level, students should be introduced to energy primarily through energy transformations.
Students should trace where energy comes from (and goes next) in examples that involve several
different forms of energy along the way: heat, light, motion of objects, chemical, and elastically
distorted materials. To change something's speed, to bend or stretch things, to heat or cool them, to
push things together or tear them apart all require transfers (and some transformations) of energy.
Food, gasoline, and batteries obviously get used up. But the energy they contain does not disappear;
it is changed into other forms of energy.
Identify forms (e.g. mechanical, chemical) and types (e.g., potential, kinetic) of
energy and their characteristics.
MEMORIZE
1. Friction is not energy. Friction is a force.
2. Energy is the ability to do work or supply heat.
3. Work is heat and heat is work. Work is the transfer of energy to move
an object.
4. Heat is not a form of energy but a method of transferring energy.
FIRST LAW OF THERMODYNAMICS – Energy is neither created nor destroyed. Energy is merely
transformed or changed from one form to another.
SECOND LAW OF THERMODYNAMICS – Heat can’t pass from a colder to a hotter body. And no machine
is 100% efficient. Some heat is lost to the environment and some sound is lost.
TWO TYPES OF ENERGY - Potential (Position, An object’s energy stored in matter due to position
relative to other objects). Kinetic (Moving, the energy of a moving object). A football in the air has both
types of energy.
KE = ½(m times v times v) or ½ mas times velocity squared.
PE = m times g times h. mass of the object times the gravitational pull on the object times the height
of the object.
o Potential energy is stored energy. Kinetic energy is energy of motion.
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Mechanical energy is the total potential plus the total kinetic energy.
THE ELEPHANT WITH A “P” ON HIS SWEATER JUMPS OFF A CLIFF.
Potential
G - Gravitational
E - Elastic
N – Nuclear (energy in atoms nucleus)
C – Chemical (energy in chemical bonds)
Kinetic
M - Mechanical
E – Electric (moving electrons)
R – Radiation or EM
T – (Thermal or heat)
S – Sound.
Common Energy Transformations
1. Different types of stoves are used to transform chemical energy of fuel (gas, coal, wood, etc.)
into heat. Heat can then make water into steam and turn turbines to make electricity.
2. Solar collectors can be used to transform solar energy into electrical energy.
3. Windmills make use of the kinetic energy of the air molecules, transforming it into mechanical
energy that turns turbines to make electrical energy.
4. Hydroelectric plants transform the kinetic energy of falling water into electrical energy.
5. A flashlight converts chemical energy stored in batteries to light energy and heat. Most of the
energy is converted into heat, only a small amount is changed into light energy.
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Demonstrating knowledge of energy transformation and transfers (e.g. , heat
transfer, energy conversion) in a system.
A slightly more sophisticated proposition is the semi-quantitative one that whenever some energy
seems to show up in one place, some will be found to disappear from another. Eventually, the energy
idea can become quantitative: If we can keep track of how much energy of each kind increases and
decreases, we find that whenever the energy in one place decreases, the energy in other places
increases by just the same amount.
The energy that is transferred into or out of a system is heat transfer.
In a closed system, if one substance loses heat then another substance must gain heat.
Heat of fusion is the amount of heat it takes to change from a solid to a liquid or the loss of
energy in going from a liquid to a solid.
Latent heat – The heat that is required to change a substance from one state to another.
Heat of vaporization – the amount of heat that it takes to change from a liquid to a gaseous
state.
Convection is not so much an independent means of heat transfer as it is an aid to transfer of heat
by conduction and radiation. Convection currents appear spontaneously when density differences
caused by heating (conduction and radiation) are acted on by a gravitational field.
Medium needed
How many substances
or mediums
Travel in Outer space
Conduction
Yes
Convection
Yes
Radiation
No
2 or more
No
1 one
No
None
Yes
Heat travels through
a heated solid or
between two heated
solids that are
touching
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Heat travels through
a fluid (air or liquid)
because of changing
density. Warm fluids
have a larger volume
as molecules move
faster and farther
apart so they are less
dense.
Heat transfer as the
result of
electromagnetic
waves of traveling
photons. The sun
warms the earth by
emitting radiant
energy. Photons are
packets of energy.
Applying knowledge of the gas laws (e.g. Boyle’s law and Charles’s law).
The behavior of gases—such as their compressibility and their expansion with temperature—may
be investigated for qualitative explanation; but the mathematics of quantitative gas laws is likely to
be more confusing than helpful to most students.
PRESSURE is the force exerted on each unit of area of a surface. Pressure is measured in a unit called
Pascal.
Temperature, Pressure, and Volume are related.
Temperature
Boyle’s Law
Charles’s Law
No Change
If temperature goes up
Pressure
If Pressure goes up
No Change
If temperature goes
Then Pressure goes
up. A tire on a hot day up because volume
or a steel pressure
does not change.
cooker.
Volume
Volume goes down.
Think of a squeezed
balloon.
Then volume goes up.
Think of the balloon
Amber in a hot car.
No Change.
Thermometers are an example of a one object with a constant volume (thermometer) and one
with a changing volume (alcohol or mercury inside). When the temperature goes up, the liquid
expands inside because the volume does change.
Analyzing phase diagrams (e.g., heat versus temperature) and the flow of
energy during changes in states of matter.
The horizontal line where a solid object melts and a liquid object freezes is important. On the
horizontal line, energy is being added (melting) or lost (freezing) BUT THE TEMPERATURE
REMAINS THE SAME because the energy is being used to overcome the intermolecular forces.
Heat capacity of an object is the amount of heat energy that it takes to raise the temperature of
the object by one degree.
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UNDERSTANDING ELECTRICITY AND MAGNETISM
Identify the characteristics of static electricity and explaining how it is
generated.
A plastic rod that is rubbed with fur or similar object will become electrically charged and will attract
small pieces of paper. The plastic rod gathers electrons while the fur loses electrons. This is a change
creating positive and negatively charged objects.
NEUTRAL OBJECT – A neutral object has no net change. The plastic rod and fur are initially neutral.
CONDUCTORS – Materials through which electric charges can easily flow. Think metals.
INSULATOR – A material through which electric charges do not flow easily, it at all. Think non-metals.
GROUNDING – Charges can be removed from an object by connecting it to earth through a conductor.
The removal of electricity by conduction is called grounding.
Electrically charged objects share these characteristics.
1. Like charges repel one another.
2. Opposite charges attract each other.
3. Charge is conserved.
Applying knowledge of the flow of electrons in circuits including the
relationships between voltage, resistance and current.
ELECTRIC CIRCUIT – An electric circuit is a path along which electrons flow.
LOAD – The light, ringing bell, television, in a circuit is an example of a load. A load is any device that
uses energy.
VOLTAGE – The energy behind the moving electrons in a circuit. Think of a water faucet. The more I cut
it on the more voltage.
CURRENT – The number of electrons per second that flow past a given point. Think of water leaving the
water hose after going through the water hose.
RESISTANCE – The ability of the material to oppose the flow of electrons through. Think of the friction of
the water hose one the water as the water goes through it. The longer the wire the more the
resistance. The thinner the wire the more the resistance. Think of a long water hose (high resistance)
and think a thick wide water hose has less resistance compared to a thin narrow hose. Compare a
garden hose to a hose on a fire truck.
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SWITCH – A switch is a device that opens or closes on a circuit. If you press a buzzer and it rings, the
buzzer is acting as a switch.
Comparing and Contrasting series and parallel circuits and how they transfer
energy.
Series Circuit
How many paths for the
electricity.
If one light goes out.
If I add a light
Only one
All the lights go out.
The rest get dimmer because
resistance increases.
Parallel
One or more.
The other lights stay on.
The brightness stays the same.
Since there are other paths the
resistance stays the same.
Recognizing the characteristics and uses of magnetic domains, magnets, and
magnetic fields.
Two ways to get rid of a magnet – hit it really hard making the electrons and their fields random. Or
making the object really hot giving the electrons enough energy to become random.
MAGNETIC FIELD – The space around a magnet where its force will act on objects.
Magnetism is the result of electrons in motion.
MAGNETIC DOMAIN – When electrons all spin in the same direction and set up magnetic fields going in
the same direction inside the metal object.
You can make a magnet out of an iron nail by repeatedly stroking the nail in the same direction with
another magnet.
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BAR MAGNET – The magnets on your refrigerator. If you break the magnet in half, each piece will still be
a magnet.
Magnets have a north and south pole. Opposite sides attract and the same sides repel.
NIC – Nickel, Iron, and Cobalt - three elements that are metals and easily become magnets or electro
magnets.
Demonstrating knowledge of the relationship between electricity and
magnetism and applications of electromagnetism and electromagnetic
induction (e.g., motors, generators, transformers).
ELECTROMAGNET - A magnet can be made out of a coil of wire by connecting the ends of the coil to a
battery. When the current goes through the wire, the wire acts in the same way that a magnet does.
This is called an electromagnet.
An electromagnet can be made more powerful in four ways.
1. Make more coils.
2. Move the coils closer together.
3. Put an iron core (nail) inside the coils.
4. Use a stronger battery source.
o Magnets and Electricity When the battery is disconnected, the compass
would point north. Notice the compass changes when the positive and
negative are reversed on the battery.
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
hese special properties of magnets can be used to make electricity. Moving
magnetic fields can pull and push electrons. Some metals, like copper
have electrons that are loosely held. They can be pushed from their shells
by moving magnets. Magnets and wire are used together in electric
generators.
GENERATOR – A device that turns rotary mechanical energy into electrical energy.
TURBINES – Turbines are rotary engines that extract energy from moving fluids like air or water.
Turbines are attached to electrical generators which actually convert the mechanical energy in the
turbine into electricity.
Transformer – An electrical device that either increases or decreases the electricity voltage.
Step up transformer - Electricity comes in on a few coils and leaves on a lot of coils. Increasing voltage.
Step down transformer – Electricity comes in on a lot of coils and leaves on only a few coils. Decreasing
voltage.
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IDENTIFYINYING THE PROCESSES INVOLVED IN THE TRANSFORMATION OF
MECHANICAL ENERGY INTO ELECTRICAL ENERGY AND THEN THE TRANSMISSION
OF ELECTRICAL ENERGY.
Almost any form of energy can be transformed into another form. Often it is mechanical energy that is
transformed into electrical energy. Examples:
Hot gases or steam: Heat produced by nuclear reactions or the combustion of fossil fuels can be used to
boil water or create steam. Alternatively solar water can be captured to heat the water.
Water: As is seen in hydroelectric dams, the natural flow of water can be used to drive a turbine.
Wind: Naturally occurring wind can be collected using windmills, which directly link to the turbine.
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UNDERSTAND THE PROPERTIES OF WAVES, SOUND AND LIGHT.
Comparing and contrasting characteristics of longitudinal waves and transverse
waves.
Wave length should be the property receiving the most attention but only minimal calculation.
Disturbance – the initial event or vibration that starts the wave.
Wave – a rhythmic disturbance which travels through space (EM waves) and matter.
There are two types of waves.
T T T Transverse waves – the particles in the waves move perpendicular to the movement of energy.
The waves go up and down and the energy goes across.
L o o o o ngitudinal waves or compressional waves – the particles in the waves move parallel to the
movement of energy.
TTTransverse wave - crest, trough, rest position, amplitude (going up or going down),
wave length, nothing
Loooongitudinal wave – rarefraction, compression, wavelength.
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FOR OUR PURPOSES – Light waves are the example used for transverse waves and sound waves are
the example used for longitudinal or compression waves.
Parts of a Transverse wave – crest, trough, rest position, amplitude, wave length.
Parts of a Longitudinal wave – compression, rarefaction, and wave length.
FREQUENCY – The number of waves that pass a given point in one second. Think of a runners on a track
crossing a line.
Long waves have a low frequency and short waves have a high frequency.
SPEED of wave SPEED (V) = (wavelength)(frequency).
Analyzing how the behavior of waves is affected by the medium (e.g., air, water
solids) through which the waves are passing.
REFRACTION – The bending of waves as they enter a new medium. As EM waves enter the atmosphere
or waves enter water, the speed of the part in the new medium decreases.
REFLECTION – Waves that bounce of an object.
Sound waves need a medium in which to spread. Light waves are EM (electromagnetic) waves and do
not need a medium.
Sound travels fastest in solids. Slows down in a liquid. And is the slowest in air.
Light travels the fastest in outer space, slower in air, slower in a liquid and slowest in a transparent solid.
Absorption – when the wave is absorbed by an object. Heat is absorbed by black objects.
When I see white all the colors are being reflected. When I see black, no light waves are being reflected
to my eyes. When I see a red shirt, red light waves are being reflected to my eyes.
Analyzing the phenomena of reflection, refraction, interference, diffraction,
polarization, dispersion, and absorption.
REFLECTED – When light hits a surface, it is reflected. The angle of incoming light is the ANGLE OF
INCIDENCE) and the light leaves at the same angle called the ANGLE OF REFLETION. You see objects
when the reflected light hits your eyes.
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DIFFUSE REFLECTION – When light hits a rough surface, the light is scattered in many different
directions.
REFRACTION – When light enters a second or new medium and bends.
o refraction – Refraction is the change in direction of a wave due to a change in its
speed. This is caused by light entering a new medium. Going from air to water.
Note: Refraction does not stay in the same medium. – diffraction stays in the
same medium. Refraction – change medium. Diffraction, same medium.
o refraction of light going through a different medium. Notice in the first diagram
that when light leaves, it is at the same angle as when it entered the solid.
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DIFFRACTION – When light stays in the same medium but bends around a barrier. Or light comes under
a door.
Wave interference – When two waves meet and cross paths in the same medium.
CONSTRUCTIVE INTERFERENCE – When two crests meet and the amplitude becomes much larger. This
can also happen with two troughs meeting and there is a much larger amplitude. Energy is increased.
DESTRUCTIVE INTERFERENCE. – When a crest of one wave meets a trough of another wave creating a
lower amplitude or even the rest position. Energy is decreased.
Standing wave – 2 waves, node, antinode, wavelength. Below is a noise cancelling
headphone. Notice you hear nothing since the amplitude is zero.
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Absorption – Like water being picked up by a paper towel, energy from a wave can be absorbed. Black
clothes absorb energy and white clothes reflect energy.
Transparent Objects
Translucent Objects
Opaque
Light hits the object and is most of the light is
transmitted out the other side. Details are clear
and sharp.
Light hits the object and some light is transmitted
out the other side but the details are no longer
clearly visible. Like looking through a curtain.
Light is reflected or absorbed but does not go
through the object. No details are visible.
Demonstrate knowledge of characteristics and uses of electromagnetic
radiation.
Slow and Cold
Radio
Turn on a
radio
Used for
transmitting
data
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microwave
Used to heat
food and
deliver cell
phone
service
ELECTROMAGNETIC SPECTRUM
infraRED
Visible
ultraVIOLET
R – Red in
RoyGBiv
V - violet in
RoyGBiv
RoyGBIV.
Night vision
Causes
goggles.
sunburn and
damage on
this side of
the
spectrum
injures
humans.
hot, high frequency
X-ray
Gamma
Grabba
Gamma
Used in
Useful in
medical field field of
astronomy.
How is a mechanical sound wave (longitudingal) transmitted between astronauts? It is not
transmitted. It is converted into a transverse EM sound wave which can travel in outer space and then
converted back to a mechanical sound wave inside the astronauts space suit.
Concave mirrors and lens are thinner in the middle and thicker or the top and bottom.
Convex mirrors and lens are thicker in the middle and thinner on the top and bottom. Think of a santa
clause belly.
Real images - Concave mirrors and convex lenses can produce real images.
Fiber optics – use the internal reflection of light and are used to carry telephone messages and are
used to carry light inside our body to see inside our throats etc.
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Demonstrate knowledge of the properties of sound and light in everyday
phenomena (e.g. echoes, Doppler effect, magnification, and rainbows).
Sound (this is not a EM radio wave!)
T T T Transverse wave
Mechanical wave – needs a medium
Light (this is an EM wave)
Looooongitudinal wave.
EM wave – think Empty it does not need a
medium.
Produced by a vibrating medium (solid liquid or
Produced by vibrating electrons that send out
gas)
photons which are packets of energy.
Travels fastest in a solid then liquid then gas and
All waves travel the fastest and at the same speed
cannot travel in outer space. It can’t travel in space in empty outer space. They slow down and
because there are no particles to vibrate.
separate in solids, liquids and gases.
Echos – are sound waves being reflected by a mediumand returned to your ear. .
Rainbows – are light waves being refracted.
Refraction and Reflection in
a drop
since water is more dense
than air, light is refracted as
it enters the drop- red is
bent less, blue more some of
the light will reflect off the
back of the drop if the angle
is larger than the critical
angle (48° for water) the
light is then refracted again
as it leaves the drop, the
colors of white light have
been dispersed.
blue light will leave the drop
at an angle of 40° from the
beam of sunlight
red light will leave the drop
at an angle of 42° from the
beam of sunlight
this process generates the
primary rainbow ->
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Notice you can’t see two colors from one drop because the
wavelength of the other colors don’t come to your eye.
Only one wavelength per drop.
However, you can not see
the blue light and red light
refracted from the same
drop!!
So, many drops are involved
in producing the rainbow....
Loudness – The amplitude of a sound wave determines the loudness. Large amplitudes are loud and
have a large intensity of energy.
Intensity – The intensity of a sound wave is the amount of energy in a wave it is similar to loudness but
if you think about it, loudness is subjective.
Frequency – The pitch of sound is based on how many waves are going by. High frequency means high
pitch. Slow means low.
Doppler effect – A duck swimming sends out round waves of energy. As the duck moves forward so the
circles in front are squeezed together (high frequency and pitch). The waves behind spread out as the
duck moves away (slow frequency and low pitch). THINK OF RACE CARS.
o Doppler shift with light. An object sending out light moving toward you shifts to
blue (shorter wave length) and the light shifts to red when the object is moving
away (longer wave length).
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Color – The color of the shirt is the color being reflected to my eye the other colors are being absorbed.
Noise – Sound waves that do not happen with regularity and which are unpleasant are called noise.
Think of static.
Demonstrating knowledge of the relationship between properties of waves and
how they are perceived by humans (e.g., color, pitch)
When we refer to light, we are usually talking about a type of electromagnetic
wave that stimulates the retina of the eye, or visible light.
Color – Each individual wavelength within the spectrum of visible light represents
a particular color.
White – when all the colors are reflected to my eyes I see white.
Black – when all the colors are being absorbed and no light waves are reaching
my eyes, I see black.
o
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
When we see red, all the colors are being absorbed except red which is
being reflected.

When we see black, it is because all the colors are being absorbed and
no colors are being reflected.
Noise – Sound waves that do not happen with regularity and which are unpleasant are called noise.
Think of static.
o Primary colors of light – red, blue, gree
o Primary colors of pigments – yellow, cyan, magenta.
o
- Comparison of Additive and Subtractive Primay Colors
Secondary colors of one system serve as the primary colors for the other.
-
VISIBLE LIGHT
R –red slower frequency
and colder
ROYGBIV
So the hottest fires are
blue/violet in color and
the new cooler lightbulbs
put out more of a red
color.
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V – violet and blue are
faster and hotter.
30
UNDERSTAND THE RELATIONSHIPS AMOUNG FORCE, MASS, AND THE
MOTION OF OBJECTS.
The force/motion relationship can be developed more fully now and the difficult idea of inertia be
given attention. Students have no trouble believing that an object at rest stays that way unless acted
on by a force; they see it every day. The difficult notion is that an object in motion will continue to
move unabated unless acted on by a force. Telling students to disregard their eyes will not do the
trick—the things around them do appear to slow down of their own accord unless constantly pushed
or pulled. The more experiences the students can have in seeing the effect of reducing friction, the
easier it may be to get them to imagine the friction-equals-zero case.
COMPARING TYPES AND CHARACTERISTICS OF FORCES (e.g. frictional and
gravitational) and analyzing the effects of forces on objects.
Dynamics – is the study of the relationship between motion and the forces affecting motion.
Force – Force causes motion.
Heat is work and work is heat.
If I go to the moon, the mass of my science book stays the same but the weight changes.
Mass
Mass is the amount of matter in an object.
Mass stays the same
Weight
Weight is the measure of the pull of gravity of a
planet or moon on an object.
Weight changes.
Mass is also a measure of an objects resistance to acceleration (going faster, stoping or changing
positions).
Momentum – Every object in motion has a property called momentum. Momentum = mass times
velocity (speed).
The greater the momentum of an object, the more force it takes to stop it. Harder to stop a train at 10
miles per hour then it is to stop a first grader at 10 miles an hour.
FRICTION – Surfaces that touch each other have a certain resistance that is called friction.
Friction – goes in the opposite direction an object is moving.
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Friction depends on 1) the type of surfaces touching and 2) how hard the surfaces are touching.
Four types
1. Static friction – two surfaces in contact that are not moving. The table and the floor.
2. Rolling friction – friction of a car wheel.
3. Sliding friction – pushing a box across the floor or your shoe on the ground.
4. Fluid friction – friction in air (air resistance) and liquids (water).
Analyzing the relationship between the displacement, velocity, and acceleration
of an object graphically, algebraically, and in written form.
To have movement, there must be a change in distance between two objects.
Speed is how fast and object is traveling. Speed = distance / time.
Velocity - gives me the direction as well as the speed. How fast and object is traveling and in which
direction it is traveling.
Instantaneous Speed – speed at a given instant.
Centripetal force – When an object moves in a circle, the centripetal force is the force that directs the
object toward the center of the circle and keeps it the object from going in a straight line. The earth’s
gravity is the centripetal force that keeps a satellite and the moon going in a circle.
Average Speed - The average of all instantaneous speeds. Total distance / Total time.
ACCELERATION - Is the rate at which an object changes velocity. Said another way it is the change in
speed (faster or slower) or the change in direction (going in a circle).
Acceleration = (final velocity – starting velocity) /time.
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Using Math – This is easy.
The stream is traveling down river at 4 mph. The man in the boat is rowing from one side of the
river to the other at 3 mph. The river is 3 miles across. At the end of an hour, how far did he row. This
is a right triangle with a = 3, b = 4. 3 squared + 4 squared = x squared. 9 + 16 = 25. The square root of
25 = 5 so he traveled 5 miles from where he started.
Newton’s laws of motion and applying them to everyday situations.
Newton’s Three Laws of Motion
1. The law of inertia –Objects at rest will remain at rest until acted on by an external force and
objects in motion will remain at motion traveling at a constant velocity (at same speed in a
straight line) until acted upon by an external force. On earth, friction is an external force that
slows objects down.
2. Force = mass times acceleration. Memorize the formula. If a net force acts on an object, it will
cause the acceleration of an object (go faster, slower, stop, change direction).
3. For every action, there is an equal but opposite reaction. When I kick a soccer ball, I exert an
equal but opposite force on the ball and the ball exerts a force on your foot. Don’t believe me,
try kicking a wall.
PUSH AND PULL – Pushing a table or pulling a bowstring applies a muscular force when the muscles
expand and contract. This is an elastic force when any object returns to its original shape (your muscles
or the bow string).
-
Yes – for every action there is an equal but opposite reaction. When he pulls, an unbalanced
force is applied from wheels to ground and ground to wheels. So they don’t cancel. No – tree did
not move. No. Must move to do work.
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RUBBING – Friction opposes (goes in the opposite direction) the motion of one surface going past
another. The air hitting your face on a bicycle or the friction of the ground on a tire.
PULL OF GRAVITY – Any two objects, any two molecules, any two atoms have a force of attraction
between them called gravity. Basically, positive electrons of one object are attracted to negative
electrons of another object and vice a versa.
All masses are attracted to other masses (gravity)
Gravity is changed by mass.
If the mass of one or both of the objects is increased,
then the gravity between them is also increased.
More Mass/Gravity
Less Mass/Gravity
Gravity is changed by distance
If the distance between the objects is increased, then
the gravity between them is decreased.
The amount of gravity between two objects is called weight.
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FORCES ON AN OBJECT AT REST – When all the forces on an object are balanced, the law of inertia says
that the object does not move and continues to remain at rest. A boat wants to float down the river
because of the force of the water but the force of the rope holding the boat to the dock is greater and
the boat does not move.
FORCS ON A MOVING OBJECT – When forces are balanced, the law of inertia says that the object
continues traveling at the same speed and in the same direction.
Moving -
Not Moving
-
INERTIA AND CIRCULAR MOTION – The high banking of a curved race tack and the friction between the
wheels and the road keep an object moving in a circle called centripetal force.
Using Math
Which has more momentum a 3600 kilogram truck moving at 8 kilometers per hour or an 1800 kilogram
truck moving at 16 kilometers per hour.
Momentum (force) = mass times acceleration (speed).
Truck = 3600 kg x 8 km/hr = 28800 kg/km/hr
Car = 1800 kg x 16 km/hr =28800 kg/km/hr.
What if the truck and car are moving at the same speed of 8 kilometers per hour
The car has ½ the momentum. Car = 1800 kg x 8 km/hr = 14400 kg/km/hr.
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APPLYING KNOWLEDGE OF CONEPTS OF WORK, POWER, EFFICIENCY, AND
MECHANICAL ADVANTAGE.
Energy
The ability to do work.
Force
The method of transferring energy from one object to another.
Work
Work is done on an object when a force is applied and the object moves
some distance. IF the object does not move, no work is done.
Work = force times distance.
Power
Power is the rate at which work is done or how fast work is done. Power =
the amount of work divided by time. Walking and running the same distance
do the same amount of work but running requires more power.
Efficiency
The law of conservation of energy says that energy cannot be created or
destroyed. It may be transformed from one form to another but the total
amount of energy never changes. Efficiency is the relationship between the
energy input and the energy output. A car loses some efficiency as energy is
transformed to heat and sound rather then making the car move.
% Efficiency = useful energy produced times 100 divided by total energy used.
Mechanical Advantage
There are two types of mechanical advantage.
1. Ideal mechanical advantage – no energy is lost from friction, heat,
light, sound, etc.
2. Actual mechanical advantage – The mechanical advantage the is
found in the real world where some energy is converted into wasteful
forms that are not useful.
Remember if distance goes up, force goes down but total work is always
the SAME. Think of a ramp compared to stairs.
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I work to make money to buy my lovely wife some joules.
Ask me what power is measured in? Watt?
I use force to open up my bag of fig neutons and eat them.
So work is measured in joules, power is measured in watt, and force is measured in neutons.
Acceleration is measured in m/s2.
Sound is measured in hertz because it hurts my ears.
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IDENTIFYING TYPES AND CHARACTERISTICS OF SIMPLE MACHINES.
6 types of Simple Machines
1.
2.
3.
4.
5.
Inclined plane
Lever
Wheel and axle
Pulley – Changes direction of the force.
Wedge – two inclined planes – the wedge moves doing the work over a greater distance so
less force.
6. Screw – an inclined plane wrapped around.
Compound machines are two or more simple machines working together. A wheelbarrow is a
lever and a wheel and axle working together.
Increase efficiency by decreasing friction.
3 types of levers
See saw, scissors, pulling a nail with a hammer.
First class lever = The fulcrum is between the
effort force and resistance force.
Second class lever = The resistance force is
between the effort force and the fulcrum.
Wheel barrow, pecan cracker, or a bottle opener.
Third class lever = The effort force is between the
resistance force and the fulcrum.
Raking leaves, hitting a baseball, using a fishing
rod.
First class lever
Second class lever
Third Class lever
Middle
Fulcrum pivot.
Resistance
Effort force
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Effort Force
Effort Force
Resistance force
Resistance force
Fulcrum pivot
Fulcrum pivot.
Table of Simple Machines
Simple
Machine
Description
What it does
Examples
Lever
A stiff structure that pivots on a
support called a fulcrum
Lifts or moves loads
Shovel Nutcracker
Seesaw
Crowbar
Elbow
Tweezers
Bottle opener
Pulley
A grooved wheel with a rope or
cable around it
Moves things up, down, or
across
Flag pole
Crane
Curtain rod
Tow truck
Mini-blind
Bicycle chain
Wheel
and axle
A wheel that turns about an axle
through its center; both wheel and
axle move together
Lifts or moves loads
Ferris wheel
Bicycle pedal
Bicycle wheel
Car wheel
Wagon wheel
Doorknob
Pencil sharpener
Wind-up hose
The Lever Family
Inclined Plane Family
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Inclined
plane
A sloping surface connecting a
lower level to a higher level
Things move up or down it
Wheelchair ramp
Slide
Stairs
Escalator
Slope
Wedge
An object with at least one
slanting side ending in a sharp
edge
Cuts or spreads an object
apart
Knife
Pin
Nail
Chisel
Ax
Hatchet
Fork
Snowplow
Front of a boat
Screw
An inclined plane wrapped around
a cylinder
Holds things together or lifts
Screw
Jar lid
Vise
Bolt
Drill
Corkscrew