SEMESTER 2 EXAM REVIEW
What is science?
Science is our attempt to understand ________.
A:
B:
C:
D:
the natural universe around us
the origins of life on other planets
the why of existence
an attempt to explain astrology
SEMESTER 2 EXAM REVIEW
What is science?
Science is our attempt to understand ________.
A: the natural universe around us
Branches of Science
What branch of the sciences is most often
concerned with the basic particles that make up
matter?
A: physics
B: chemistry
C: geology
D: A and B
E: A and C
Branches of Science
What branch of the sciences is most often
concerned with the basic particles that make up
matter?
D: A (physics) and B (chemistry)
Laboratory Methods/Lab Safety
When doing a classroom investigation
laboratory, when should you substitute other
equipment from those listed in the materials?
Laboratory Methods/Lab Safety
When doing a classroom investigation
laboratory, when should you substitute other
equipment from those listed in the materials?
Only when instructed by your teacher
Laboratory Methods/Safety
Under what circumstances should you report an
injury during a classroom investigation
laboratory?
Laboratory Methods/Safety
Under what circumstances should you report an
injury during a classroom investigation
laboratory?
Always report an injury, however minor.
Experimental Design
Inigo plans to conduct an experiment using three plants. His hypothesis is
that the plant receiving the most sunlight at the end of three months will
show the most growth. In his plan above, he has listed the types of plants,
and how much water, fertilizer, and sunlight each plant will receive. What
could Inigo do to improve his experiment?
Experimental Design
Inigo plans to conduct an experiment using three plants. His hypothesis is
that the plant receiving the most sunlight at the end of three months will
show the most growth. In his plan above, he has listed the types of plants,
and how much water, fertilizer, and sunlight each plant will receive. What
could Inigo do to improve his experiment?
Inigo should use the same types of plants.
Experimental Bias
Johannes Kepler believed that all planets must
circle the sun in perfectly circular orbits.
However, the data did not match Kepler’s
original theory. In order to exhibit the scientific
trait of honesty and to eliminate experimental
bias, what did he do?
Experimental Bias
Johannes Kepler believed that all planets must
circle the sun in perfectly circular orbits.
However, the data did not match Kepler’s
original theory. In order to exhibit the scientific
trait of honesty and to eliminate experimental
bias, what did he do?
Abandoned his theory
Experimental Bias
A team of researchers records the progress of a
chemical change by watching the color change of
the products. What is one way to avoid bias in
this research?
Experimental Bias
A team of researchers records the progress of a
chemical change by watching the color change of
the products. What is one way to avoid bias in
this research?
Use an instrument to measure color precisely,
such as a spectrometer.
Drawing Conclusions
Even though the speed of light is 1,079,252,848.8
km/h, scientists know it can take hundreds or even
millions of years for starlight to reach Earth. Which
statement is incorrect?
A: The stars are very far away.
B: The Sun and stars are very old.
C: The laws of science are universal.
D: Different scientific laws apply on the stars and
on Earth.
Drawing Conclusions
Even though the speed of light is
1,079,252,848.8 km/h, scientists know it can
take hundreds or even millions of years for
starlight to reach Earth. Which statement is
incorrect?
D: Different scientific laws apply on the stars
and on Earth.
Science Methods
Scientific papers often describe the meanings of
words in great detail. Why?
Science Methods
Scientific papers often describe the meanings of
words in great detail. Why?
To clearly communicate information
Science Methods
For scientists, what is the most important
advantage of publishing research in a peerreviewed journal instead of writing a book?
Science Methods
For scientists, what is the most important
advantage of publishing research in a peerreviewed journal instead of writing a book?
Articles in peer-reviewed journals are checked
for accuracy by many scientists.
Science Methods
A scientific paper describing an experiment will
most likely describe all EXCEPT _______.
A.
B.
C.
D.
procedure
methods
conclusions
opinions
Science Methods
A scientific paper describing an experiment will
most likely describe all EXCEPT _______.
D. opinions
Experimental Design
Some researchers in a field known as string theory suggest
that gravity might get weaker than expected at extremely
small distances. If this hypothesis is verified repeatedly
through reliable observations, which is NOT a likely
consequence?
A: Scientists will have to take this into account when studying
gravity at small scales.
B: Scientists will have to determine when the old theories still
apply.
C: All old theories of gravity will be thrown out, and
researchers will start over.
D: Scientists will have to determine the conditions in which
the new theories are most useful.
Experimental Design
Some researchers in a field known as string
theory suggest that gravity might get weaker
than expected at extremely small distances. If
this hypothesis is verified repeatedly through
reliable observations, which is NOT a likely
consequence?
C: All old theories of gravity will be thrown
out, and researchers will start over.
Scientific Laws and Theories
Einstein’s theory of general relativity was accepted because even
though Newton’s law of universal gravitation worked well for almost all
measurements, it tended to predict motion inaccurately when
gravitational forces were very strong. And yet, when a spacecraft is
sent to the Moon or to a distant planet, it is Newton’s law of universal
gravitation, and not Einstein’s theory of general relativity, that is used
to predict the path of the spacecraft. Why?
A: Einstein’s general relativity works only on the scale of galaxies.
B: Einstein’s general relativity is untested.
C: Newton’s theory of universal gravitation works well under the
conditions likely to be encountered by spacecraft.
D: Einstein’s general relativity makes poor predictions for the motions
of spacecraft.
Scientific Laws and Theories
Einstein’s theory of general relativity was accepted because
even though Newton’s law of universal gravitation worked
well for almost all measurements, it tended to predict motion
inaccurately when gravitational forces were very strong. And
yet, when a spacecraft is sent to the Moon or to a distant
planet, it is Newton’s law of universal gravitation, and not
Einstein’s theory of general relativity, that is used to predict
the path of the spacecraft. Why?
C: Newton’s theory of universal gravitation works well under
the conditions likely to be encountered by spacecraft.
Scientific Theories
Which statement is NOT true?
A: If two scientific theories make exactly the same
predictions, there is no way for an experiment to distinguish
between the two theories.
B: If two scientific theories both explain the same set of data,
scientists will often prefer the simpler of the two theories.
C: If two scientific theories explain data under different
conditions, then the two theories cannot both be right.
D: If two scientific theories each explain data under different
conditions, then the two theories might be combined into a
third theory.
Scientific Theories
Which statement is NOT true?
A: If two scientific theories make exactly the
same predictions, there is no way for an
experiment to distinguish between the two
theories.
Where is the best place to find a scientific
definition of the word “reaction?”
The best place to find a scientific definition of
the word reaction is in a science dictionary or
science reference book.
Measurement
Using their feet, Mary and Eliza both measure
the length of a football field five times. While
Mary is the more accurate of the two, Eliza is
more precise. Explain.
Measurement
Using their feet, Mary and Eliza both measure
the length of a football field five times. While
Mary is the more accurate of the two, Eliza is
more precise. Explain.
Mary’s measurements were closer to the actual
value. Eliza’s measurements were closer
together in value.
Scientific Notation
A light-year is a unit that astronomers use to
measure large distances in space. A light-year is
equal to 9.461×1012 kilometers. How many
meters is in a light-year?
Scientific Notation
A light-year is a unit that astronomers use to
measure large distances in space. A light-year is
equal to 9.461×1012 kilometers. How many
meters is in a light-year?
9.461×1012 km x 103 m = 9.461×1015 m
1 km
Experimental Data Analysis
What are 2 problems with this data table?
Experimental Data Analysis
What are 2 problems with this data table?
1. Significant figures are not used correctly.
2. Units of measure were not included.
Data Analysis and Density
You decide to use an electronic balance and a water displacement vessel
to measure the density of pennies, but you run into a problem. Examine
the table to discover the nature of the problem.
How does this new information change your investigation?
Data Analysis and Density
You decide to use an electronic balance and a water displacement vessel
to measure the density of pennies, but you run into a problem. Examine
the table to discover the nature of the problem. The mass of the penny
depends on the year it was minted.
How does this new information change your investigation?
Density will depend on year minted.
Data Analysis and Density
Densities of some metals are shown. A 10-gram
sample of each metal must differ in ?
Data Analysis and Density
Densities of some metals are shown. A 10-gram
sample of each metal must differ in volume.
D = m/v, so if the mass of each sample is 10 g, the
volume is different if densities are also different.
Quantitative vs. Qualitative
Why is the use of quantitative data important in
scientific arguments?
Quantitative vs. Qualitative
Why is the use of quantitative data important in
scientific arguments?
The use of quantitative data allows researchers
to compare their observations.
Data Analysis and Density
Group A measures the density of a block of metal
to be 32 g/cm3. Group B measures the density of
the same block to be 64 g/cm3.
What are probably the sources of the discrepancy?
What is probably NOT a source of discrepancy?
Data Analysis and Density
Group A measures the density of a block of metal to
be 32 g/cm3. Group B measures the density of the
same block to be 64 g/cm3.
What are probably the sources of the discrepancy?
- Incorrect measurements of mass or volume
- Using an incorrect formula
What is probably NOT a source of discrepancy?
- Measuring density where gravity has a different
value.
Gas Laws
At constant pressure, the volume of a gas is
reduced from 1.0 liters to 0.4 liters. If the
beginning temperature is 298 K, what is the final
temperature?
V1 = 1.0 L
T1 = 298 K
V2 = 0.4 L
T2 = ?
Gas Laws
At constant pressure, the volume of a gas is
reduced from 1.0 liters to 0.4 liters. If the
beginning temperature is 298 K, what is the final
temperature? v1 = v2
V1 = 1.0 L
T1 = 298 K
V2 = 0.4 L
T2 = ?
T1
T2
1.0 L = 0.4 L
298 K
T2
(1.0 L) T2 = (0.4 L)(298 K)
T2 = (0.4 L)(298 K) = 119 K
(1.0 L)
Atomic Structure
If you wanted to know whether an atom is
oxygen or nitrogen, you should find out how
many ____ it has.
Atomic Structure
If you wanted to know whether an atom is
oxygen or nitrogen, you should find out how
many protons it has.
Most metallic elements have all of these
properties EXCEPT ______.
A.
B.
C.
D.
having a high density
highly ductile
good electrical conductor
being easily crumbled into pieces
Most metallic elements have all of these
properties EXCEPT ______.
A.
B.
C.
D.
having a high density
highly ductile
good electrical conductor
being easily crumbled into pieces
What type of graph would best
represent the following data?
What type of graph would best
represent the following data?
A pie graph would best represent the data above.
Periodic Table Trends
The table above represents several elements that
have the same valence. What is the name of the
group to which these elements belong?
Periodic Table Trends
The table above represents several elements that
have the same valence. What is the name of the
group to which these elements belong?
The Noble Gases
Bonding
Ionic compounds are usually formed by ionic
bonding between metals and nonmetals.
Classify each as ionic or covalent.
A.
B.
C.
D.
CO2
CaCl2
H2O
C6H12O6
Bonding
Ionic compounds are usually formed by ionic
bonding between metals and nonmetals. Classify
each as ionic or covalent.
A. CO2
B. CaCl2
C. H2O
D. C6H12O6
All are covalent bonds except for B, which is ionic.
Write Chemical Formulas for the
following compounds:
1.
2.
3.
4.
5.
6.
7.
potassium nitrate
calcium sulfate
magnesium fluoride
potassium iodide
calcium nitrate
sodium sulfate
sodium nitrate
Write Chemical Formulas for the
following compounds:
1. potassium nitrate
2. calcium sulfate
3. magnesium fluoride
4. potassium iodide
5. calcium nitrate
6. sodium sulfate
7. sodium nitrate
Answers:
1. KNO3
3. MgF2
5. Ca(NO3) 2
2. CaSO4
6. Na2SO4
4. KI
7. NaNO3
Chemical Formulas
What is the chemical formula for carbon
monoxide?
Carbon dioxide?
Carbon tetrachloride?
Diphosphorus pentachloride?
Chemical Formulas
What is the chemical formula for carbon
monoxide? CO
Carbon dioxide? CO2
Carbon tetrachloride? CCl4
Diphosphorus pentachloride? P2Cl5
What is the purpose of Rose’s list
(pictured below)?
What is the purpose of Rose’s list
(pictured below)?
She is recording examples of chemical change.
According to the table, a substance that burns
with a greenish flame most likely contains
____________________________.
According to the table, a substance that burns
with a greenish flame most likely contains
either barium or copper.
Law of Conservation of Mass
A student wants to test the law of conservation
of mass by burning a sample of charcoal. When
should s/he measure the mass of the reactants?
Law of Conservation of Mass
A student wants to test the law of conservation
of mass by burning a sample of charcoal. When
should s/he measure the mass of the reactants?
She should measure the reactants before the
reaction.
Reactants
Products
Chemical Reaction Types
Use CAPITAL LETTERS or Draw a representation of
each of the following reaction types:
1. Synthesis:
2. Decomposition:
3. Single-Replacement:
4. Double-Replacement:
5. Combustion:
Be able to identify reaction type given a chemical
equation.
Chemical Reaction Types
Use CAPITAL LETTERS or Draw a representation of
each of the following reaction types:
1. Synthesis: A + B
AB
2. Decomposition: AB
A+B
3. Single-Replacement: AB + C
CB + A
4. Double-Replacement: AB + CD
CB + AD
5. Combustion: CxHy + O2
CO + H2O
Be able to identify reaction type given a chemical
equation.
Solubility
Based on the information in the table above,
what is the approximate solubility of
potassium chloride at 25°C?
Solubility
Based on the information in the table above,
what is the approximate solubility of
potassium chloride at 25°C?
Between 34.0 g and 56.3 g
Solubility
Solubility increases with temperature and
decreases with amount of solute. If you stirred
sugar into each substance, which would be able
to dissolve the least?
A: a cold glass of distilled water
B: a warm glass of distilled water
C: a cold mixture of sugar and water
D: a warm mixture of sugar and water
Solubility
Solubility increases with temperature and
decreases with amount of solute. If you stirred
sugar into each substance, which would be able
to dissolve the least?
C: a cold mixture of sugar and water
Acids, Bases, and Salts
Which substance will be located farthest toward
the alkaline side of the pH scale?
A. vinegar
B. baking soda
C. carbonated beverage
D. spaghetti sauce
Acids, Bases, and Salts
Which substance will be located farthest toward
the alkaline side of the pH scale?
B. baking soda
Acids, Bases, and Salts
Which pH measurement is MOST acidic?
A. 5.5
B. 1.2
C. 6.3
D. 3.8
E. 9.5
F. 14.2
Acids, Bases, and Salts
Which pH measurement is MOST acidic?
B. 1.2
Acid-Base Neutralization
Tali uses a graduated cylinder to measure a
sufficient amount of an acidic solution to
neutralize a basic solution, but after mixing the
solutions, she finds the product is still basic.
What is the most likely cause of her mistake?
Acid-Base Neutralization
Tali uses a graduated cylinder to measure a
sufficient amount of an acidic solution to
neutralize a basic solution, but after mixing the
solutions, she finds the product is still basic.
What is the most likely cause of her mistake?
The acid was not acidic enough or not
concentrated enough.
Motion
Consider the graph shown here (Above). What is
one benefit of displaying scientific information with
a graph?
Motion
Consider the graph shown here (Above). What is
one benefit of displaying scientific information with
a graph? A graph shows the relationship among
variables.
Newton’s Laws
According to Newton’s second law of motion,
mass times acceleration equals _____.
Newton’s Laws
According to Newton’s second law of motion,
mass times acceleration equals FORCE.
Albert Einstein developed a new theory of gravity
several centuries after Isaac Newton. Most scientists
did not accept Einstein’s theory of gravity until
observations were made, showing that light beams
from distant stars were bent by the Sun’s gravity, as
predicted by Einstein’s theory.
What is the best reason scientists could have had to
prefer Newton’s theory?
A. Newton’s theory is the one they had learned about
it in school.
B. There was no way to choose between the theories
without observational evidence.
C. Newton’s theory was easier to use.
D. Einstein would become more famous than Newton
if his theory were shown to be true.
Albert Einstein developed a new theory of
gravity several centuries after Isaac Newton.
Most scientists did not accept Einstein’s
theory of gravity until observations were
made, showing that light beams from distant
stars were bent by the Sun’s gravity, as
predicted by Einstein’s theory.
What is the best reason scientists could have
had to prefer Newton’s theory?
B. There was no way to choose between the
theories without observational evidence.
Laws of Motion
Data Analysis
Three identical tennis balls are fired from ball-cannons
at the same instant. The barrels of all three ballcannons are parallel to the ground. The table shows
the horizontal speeds of the balls. What is true of their
falling speeds?
Laws of Motion
Data Analysis
Three identical tennis balls are fired from ball-cannons
at the same instant. The barrels of all three ballcannons are parallel to the ground. The table shows
the horizontal speeds of the balls. What is true of their
falling speeds? They all fall at the same rate, 9.8 m/s2.
Newton’s Laws
If they have the same diameter and the same
force is applied to the following objects, which
one will have the MOST acceleration?
A. a glass ball
B. lead ball
C. an aluminum ball
D. a plastic ball
Newton’s Laws
If they have the same diameter and the same
force is applied to the following objects, which
one will have the MOST acceleration?
D. a plastic ball
Weight
The table (above) shows weight in Newtons on
different planets. For a person with a mass of 50 kg,
on which planet would her weight be the least?
Weight
The table (above) shows weight in Newtons on
different planets. For a person with a mass of 50 kg,
on which planet would her weight be the least?
MARS
A train slows down and then speeds up as it travels
over a hill each day. You want to determine if the train
ever slows to less than 90 km/h. You collect data and
record it in a table (above). What could you do to
determine if the train slows to less than 90 km/h?
A train slows down and then speeds up as it travels
over a hill each day. You want to determine if the train
ever slows to less than 90 km/h. You collect data and
record it in a table (above). What could you do to
determine if the train slows to less than 90 km/h?
Measure the speed between 20 and 30 seconds.
Efficiency
The efficiency of a machine is a measure of how
much of the work put into a machine is converted
to useful output work by the machine. Which
statement is true?
A. Electrical machines are more efficient than
nonelectrical machines.
B. No machine is 100 percent efficient.
C. Electrical machines are 100 percent efficient.
D. All machines are100 percent efficient.
Efficiency
The efficiency of a machine is a measure of how
much of the work put into a machine is
converted to useful output work by the
machine. Which statement is true?
B. No machine is 100 percent efficient.
Energy Sources
In a debate on alternative fuels, why would an
increased use of solar power be more favorable
than the use of oil or coal?
Energy Sources
In a debate on alternative fuels, why would an
increased use of solar power be more favorable
than the use of oil or coal?
Solar power is a renewable resource and is a
clean source of energy, and fossil fuels, such as
coal and oil, are non-renewable and release
pollutants when burned.
Energy Transfer
It was once argued that heat was a fluid, able to flow
from hot objects to cold ones. One argument in favor of
heat as a fluid was that it seemed to flow from a hot
metal bar into cold water, resulting in hotter water and
colder metal. What is one possible argument against the
heat fluid theory?
A: The observation that hot objects cool down and cool objects heat
up may be wrong.
B: We can’t see heat moving from one object to another, therefore it
can’t be happening.
C: Heat can’t be a fluid because hot air rises.
D: heat can be produced without the presence of a hot object; for
instance, by rubbing your hands together.
Energy Transfer
It was once argued that heat was a fluid, able to
flow from hot objects to cold ones. One
argument in favor of heat as a fluid was that it
seemed to flow from a hot metal bar into cold
water, resulting in hotter water and colder
metal. What is one possible argument against
the heat fluid theory?
D: heat can be produced without the presence of a hot
object; for instance, by rubbing your hands together.
Energy Transfer
Which probably transfers the least energy?
A. the vibration of an erupting volcano
B. the sound of a loud stereo
C. an ocean wave carrying a surfer
D. the infrasonic rumble of an earthquake
Energy Transfer
Which probably transfers the least energy?
B. the sound of a loud stereo
Energy Sources
Which statement is true?
A. Most of the energy produced by burning natural gas is
turned into electricity.
B. All of the energy produced by burning gasoline is
wasted.
C. Most of the energy produced by burning coal is
wasted.
D. All of the energy produced by burning wood becomes
pollution.
Energy Sources
Which statement is true?
A. Most of the energy produced by burning
natural gas is turned into electricity.
Heat Energy
According to the table below, what material
requires the least heat to raise its
temperature by 10°C?
Heat Energy
According to the table below, what material
requires the least heat to raise its
temperature by 10°C? iron
While a pan of water is boiling, what happens to
the temperature of the water?
While a pan of water is boiling, what happens to
the temperature of the water?
The temperature of the boiling water remains
constant while in the liquid state.
Energy Conversion
The temperature is higher inside a parked car on
a sunny day than outside because of the
conversion of _____ energy to _____ energy.
Energy Conversion
The temperature is higher inside a parked car on
a sunny day than outside because of the
conversion of LIGHT energy to THERMAL energy.
Nuclear Reactions
What does the diagram pictured above show?
Nuclear Reactions
What does the diagram pictured above show?
An element can change into a different element
through the process of nuclear decay.
Nuclear Fusion vs. Nuclear Fission
Nuclear fission converts small amounts of
matter into ____ amounts of _____.
Nuclear Fusion vs. Nuclear Fission
Nuclear fission converts small amounts of
matter into LARGE amounts of ENERGY.
A helium nucleus is the same as a(n) _______.
A. hydrogen nucleus
B. alpha particle
C. beta particle
D. gamma particle
A helium nucleus is the same as a(n) _______.
B. alpha particle
Radioactive Half-Life
Half-life is the
amount of time it
takes for half of a
sample to decay.
According to these data (pictured above), after how
many years would the mass of a one-gram sample of
carbon-14 decay to 1/8 gram?
Radioactive Half-Life
Half-life is the
amount of time it
takes for half of a
sample to decay.
According to these data (pictured above), after how
many years would the mass of a one-gram sample of
carbon-14 decay to 1/8 gram? 17,100 years
Radioactive Half-Life
Half-life is the
amount of time it
takes for half of a
sample to decay.
Which radioisotope in the table above would be
LEAST useful for determining the age of the
remains of a living thing?
Radioactive Half-Life
Half-life is the
amount of time it
takes for half of a
sample to decay.
Which radioisotope in the table above would be
LEAST useful for determining the age of the
remains of a living thing? Potassium-40
Nuclear Waste
Why is high-level radioactive waste from nuclear
power plants often buried deep underground?
Nuclear Waste
Why is high-level radioactive waste from nuclear
power plants often buried deep underground?
Because it can remain radioactive (which
means its nucleus continues to break down,
giving off particles and energy) for thousands
of years.
Comparison of Waves
Sound travels in a ________________ (or ______________) wave.
Electromagnetic Waves, includes light, travel in _____________waves.
Comparison of Waves
Sound travels in a compression (or longitudinal) wave.
Electromagnetic Waves, includes light, travel in transverse waves.
Slinky Demonstration
Identify which is the compressional wave and which is
the transverse wave below.
Slinky Demonstration
compressional wave
transverse wave
What makes waves different?
•
•
•
•
The _____ (solid, liquid, or gas) they travel in
How much ______ they carry
How _________ they travel
How they _______.
What makes waves different?
•
•
•
•
The medium (solid, liquid, or gas) they travel in
How much energy they carry
How fast they travel
How they look.
What causes sound?
• All waves are caused by something that ________.
• Sound Waves MUST HAVE A ______, which is a ___, ____, or ___.
•
No Medium = No _____.
• In the case of sound waves, the vibrations cause molecules of air to
______, and the energy transmits causing areas of high _______and
low _________to form as the energy is carried away from the source
What causes sound?
• All waves are caused by something that vibrates.
• Sound Waves MUST HAVE A MEDIUM (solid, liquid, or gas)
•No Medium = No Sound
• In the case of sound waves, the vibrations cause molecules of air to
vibrate, and the energy transmits causing areas of high pressure and
low pressure to form as the energy is carried away from the source
When 2 or more waves _________ and combine
to form a new wave, the process is called
______________.
________________ – ADD
Compare Wave 2 in each diagram.
_______________ - SUBTRACT
When 2 or more waves OVERLAP and combine
to form a new wave, the process is called
INTERFERENCE.
CONSTRUCTIVE – ADD
Compare Wave 2 in each diagram.
DESTRUCTIVE - SUBTRACT
Waves
What is destructive interference of sound
waves?
What effect does destructive interference have
on sound?
Waves
What is destructive interference of sound
waves? When two sound waves overlap and
cancel each other out.
What effect does destructive interference have
on sound? Destructive interference of sound
waves causes “beats,” and can cause quiet
areas in a room while music is playing.
Sound Transmission
From fastest transmission to slowest, three
media that transmit sound are _______.
A:
B:
C:
D:
water, steel, and air
steel, water, and air
air, steel, and water
steel, air, and water
Sound Transmission
From fastest transmission to slowest, three
media that transmit sound are _______.
B: steel, water, and air
Wave Frequency
In 5 seconds, 5 wavelengths of a wave pass a
certain point. What is the wave’s frequency?
Wave frequency is measured in Hertz (Hz)
Frequency = # cycles/second
Calculate frequency
What is the relationship between wavelength and frequency?
Wave Frequency
In 5 seconds, 5 wavelengths of a wave pass a
certain point. What is the wave’s frequency?
Wave frequency is measured in Hertz (Hz)
Frequency = # cycles/second
5 wavelengths = 1 Hz
5 seconds
What is the relationship between wavelength and frequency?
As frequency increases, wavelength decreases.
What is the relationship between wavelength and frequency?
What is the relationship between frequency and energy?
What is the relationship between wavelength and frequency?
AS WAVELENGTH DECREASES, FREQUENCY INCREASES.
What is the relationship between frequency and energy?
AS FREQUENCY INCREASES, ENERGY INCREASES.
Wave Properties
Because light has wave properties, at one time, scientists thought that just like
water waves or sound waves, light must move through some sort of material. They
hypothesized the existence of a substance called “aluminiferous ether,” which
carried light through space. Experiments were carried out to find the speed of
Earth through the ether, but no evidence of the ether could be found. These
experiments led eventually to Albert Einstein’s theory of special relativity, in which
the speed of light is assumed to be constant for all observers.
Which statement does NOT describe the importance of the ether hypothesis?
A: Incorrect hypotheses are never corrected, only expanded upon.
B: Incorrect hypotheses often cause scientists to develop new experiments that
produce additional data.
C: Incorrect hypotheses can give scientists ideas about what to study in the future.
D: Incorrect hypotheses must be corrected to form better hypotheses.
Wave Properties
Because light has wave properties, at one time, scientists thought that just
like water waves or sound waves, light must move through some sort of
material. They hypothesized the existence of a substance called
“aluminiferous ether,” which carried light through space. Experiments were
carried out to find the speed of Earth through the ether, but no evidence of
the ether could be found. These experiments led eventually to Albert
Einstein’s theory of special relativity, in which the speed of light is assumed
to be constant for all observers.
Which statement does NOT describe the importance of the ether
hypothesis?
A: Incorrect hypotheses are never corrected, only expanded upon.
Wave Properties
What do electromagnetic (EM) waves and sound
waves have in common? All waves…
• • How are they different?
• • • • -
Wave Properties
What do electromagnetic (EM) waves and sound waves have
in common? All waves…
• transfer energy
• can be reflected, refracted, diffracted, and can
experience interference.
How are they different?
• EM waves can travel through empty space, while sound
waves require a medium
• EM waves travel MUCH FASTER than Sound waves.
• EM waves travel at 300,000 m/s in empty space
• Sound travels at 343 m/s in air (at 20◦ C) - it cannot
travel in empty space. The speed of sound changes with
the temperature.
A scientist uses a spectrometer to measure the
wavelength of two similar stars. One of the stars
is moving away from Earth, and the other is
moving toward Earth. What is the scientist most
likely investigating?
http://en.wikibooks.org/wiki/High_School_Earth_Science/Telescopes
A scientist uses a spectrometer to measure the
wavelength of two similar stars. One of the stars
is moving away from Earth, and the other is
moving toward Earth. What is the scientist most
likely investigating?
The speed the stars are moving.
http://en.wikibooks.org/wiki/High_School_Earth_Science/Telescopes
Which are of Physical Science is most closely
related to development of radio?
A:
B:
C:
D:
electromagnetism
gravity
optics
statistics
Which are of Physical Science is most closely
related to development of radio?
A: electromagnetism
Electrical Conductivity
Pure water is not a good conductor of electricity.
How can its conductivity be increased?
Electrical Conductivity
Pure water is not a good conductor of electricity.
How can its conductivity be increased?
Add an ionic compound to the water.
Electricity
The diagram (shown below) shows a
transformer. What is the purpose of
transformers?
Electricity
The diagram (shown below) shows a
transformer. What is the purpose of
transformers? Transformers change the voltage
and current of electricity.
The world’s population has been increasing for
most of recorded history. Which is the MOST likely
hypothesis to explain this fact?
A: Better healthcare has allowed people to live
longer.
B: The number of children per family has been
decreasing.
C: Population statistics have been recorded with
increasing accuracy.
D: The number of countries in the world has
increased.
The world’s population has been increasing for
most of recorded history. Which is the MOST
likely hypothesis to explain this fact?
A: Better healthcare has allowed people to live
longer.
Why is science always changing?
Why is science always changing?
New data is always being gathered.