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6th Grade Science Essential
Vocabulary & Concepts
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A01 Process Skills & Measurement |
Picture | Core Knowledge or Concept |
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Science is the process of explaining the natural world. |
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Observing is using your senses to gather information about the world. |
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Qualitative observations describe using words, diagrams, or models. |
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Quantitative observations measure using numbers. |
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Inferring is making sense of your observation. |
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Predicting
is making an inference about a future event |
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Models
help people understand things that they cannot observe directly. |
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Communicating is the process of sharing ideas and information
with other people. |
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Metric System
(International System of Units, SI) a system of measurement based on the
number 10.
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A02 Scientific Method |
Picture | Core Knowledge or Concept |
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Scientific Method a system for investigating the universe.. |
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Problem:
Always asks a question. The problem guides the experiment |
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Background Research:
Find out what we already know about the problem, including our own
personal knowledge and research on the topic. |
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Hypothesis: A testable statement that “answers” the problem. This is
usually written in an “if, then” format. It is based on the background
research. |
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Experimental
Design: Describes how the
experiment will be performed. It is written in a list format and
contains the following sections: |
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A.
Variables: The three types are:
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B: Procedures:
a numbered list of exactly what you will be doing. |
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C. Materials:
a numbered list of exactly what you will be using. |
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D: Trials: how many times you run an experiment. |
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The results
section is the data from the experiment. It can be a table, graph, or chart. |
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An analysis
is the explanation of the data of an experiment. |
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A conclusion summarizes the experiment referring to the hypothesis and states how the experiment may be changed. |
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The Experimenting or experimentation is a method of testing scientific ideas. |
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The
PseudoScience is not science. It does not follow all of the steps of
the scientific method. It is often used to trick people. |
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The
Technology is the creation of goods and services for human use. It
uses a method called theDesign
Cycle. |
A03 Motion |
Picture | Core Knowledge or Concept |
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An object is in motion when its distance from a reference point changes. |
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Average
speed is: total distance in a given or total, time. (Like from the
start to finish line.) (The opposite is instantaneous speed, speed at a given moment in time like on a roller coaster.) Speed does not give a direction travelled. (Speed = Distance Time) |
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Velocity
is speed in a given direction. |
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Vectors or rays are arrows that can show motion and forces. |
A04 Acceleration |
Picture |
Core Knowledge or Concept |
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Acceleration is the rate
(how fast) at which velocity changes
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![]() | An accelerometer measures changes in acceleration or jerk. Electronic acelerometers are used in cars to set off
airbags and in runners' speedometers. |
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The formula for acceleration
is (final speed -
initial speed) / time. or ( Speedend - Speedstart
) / time Change in speed is (Speedend - Speedstart) ![]() |
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Scientist Galileo Galilei experimented with gravity by dropping things from a tower, rolling things down ramps, and observing the planets and moons of the solar system. |
A05 Forces, Inertia, & Newton's 1st Law |
Picture | Core Knowledge or Concept |
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A force
is a push or a pull. |
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Net force is the
sum of forces acting on an object. |
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balanced
forces: are equal and opposite. They do not cause motion |
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unbalanced
forces: are not equal. They can cause things to move. |
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Force arrows
show the magnitude and
direction of a force. The width or length can show strength. |
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Inertia
is the tendency of an object to resist change to its motion. An object's
inertia is related to its mass. |
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Mass is the amount of matter
in an object. Matter is anything that has mass and volume (takes up space.) |
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Newton’s first law of motion (aka,
The Law of Inertia) states that "an object at rest remains at rest and an object will remain in motion unless acted upon by an unbalanced force." |
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Free Body Diagrams: a standard diagram that shows all of the forces
acting on an object. The object is a box at the center with arrows pointing towards it from the direction of each force. |
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Scientist Isaac Newton was a mathematical genius who invented new types of math related to motion and forces. Evidence suggests that he may have had a form of autism. |
A06 Newton's 2nd Law: f=m*a, Friction, and Gravity |
Picture | Core Knowledge or Concept |
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Weight
(Mass * Acceleration due to gravity) is the measure of the force of
gravity upon an object. (i.e. you weigh less on the moon, but your mass is the same.) |
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Friction
is the force that one surface exerts
upon another. (i.e. sliding on gravel slows you down versus sliding on ice, rolling on wheels, a fluid water slide, or static: not moving). Its force always acts in the opposite direction to motion Friction's strength depends on
fluid friction: liquids and gasses sliding: when one or both surfaces are moving or rubbing together rolling: when one or both surfaces are spinning static: when neither surface is moving |
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The law of
universal gravitation
states that the force of gravity acts between all objects (matter) in the
universe (everything, everywhere). |
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Gravity
is the force that pulls objects towards more
massive things (like Earth). Gravity's strength varies by
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Newton’s Second Law of Motion states that the
net
force of an object is equal to the net product of it acceleration and its
mass. (i.e. a speeding car has more impact than a blowing leaf crashing into a wall) (Force = Mass * Acceleration) |
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Scientist Albert Einstein was a mathematical genius who related time, space, gravity, and mass in his theories of special relativity (Time and space) and general relativity (gravity, space, and mass.) He also defined the speed of light as a universal speed limit and related energy and matter with e=mc2. |
A08 Newton's 3rd Law: Action-Reaction & Momentum |
Picture | Core Knowledge or Concept |
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Momentum ( M ass * V elocity), Is related to kinetic energy or moving energy. |
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The
law of conservation of
momentum
states that total momentum of any group of objects remains the same unless
an outside force acts on the object.
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Newton’s third law of motion states that if one object
exerts a force on another object, the second object exerts a force of
equal strength in the opposite direction on the first object.
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Scientists Robert Goddard, the father of rocketry in the early 20th century Wernher von Braun, developed the Atlas rocket for the United States. His rockets were powerful enough for NASA's space program and, along with competing Soviet scientists created intercontinental ballistic missiles that could have destroyed the world. |
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Technology Pugh Charts: are used to check if a design meets the specifications (requirements) of a design. Usually used to compare designs (columns) against each specification (rows.) ![]() |
A09 Energy |
Picture | Core Knowledge or Concept |
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Energy Energy
is the ability to do work or cause a change. The unit of energy is the Joule. |
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Kinetic energy
is the energy of motion. It depends on mass and velocity. (i.e. a book falling) |
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Potential
energy is energy that is stored and ready to be released. (i.e. a book on a table ready to fall)
(weight is in newtons, height in meters.) formula for gravity (Earth's = 9.8 m/s2) |
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Forms of energy
and their sources
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Work is the
transfer of energy between objects. (Like a force that makes an object move.) work = force * distance (force is in newtons, distance in meters.) The unit of work is the Joule. |
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Energy conversion occurs when one type (form) of energy is changed
into another. (i.e. electricity into sound, motion into heat, etc.) |
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The law of conservation of energy states that energy can neither be
created nor destroyed. Einstein's theory e=mc2 says that energy (e) can be converted to matter (m) and vice versa (and back again). |
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Scientist Enrico Fermi, the father of American Nuclear Physics at the University of Chicago. His work is continued in the Manhattan project, Argonne National Labs, and the Fermilab Accelerator in Batavia. |
A10 Pressure |
Picture | Core Knowledge or Concept |
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Pressure is
a force spread over an area. Pressure (Force ÷ Area) Pascal (Pa)" the unit of pressure in Newtons/meter2 (i.e. the pointy end of a stick hurts more than the side of the stick) |
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Fluid a
substance whose shape can easily change. Fluids are usually liquids or gasses. In fluids, the particles (molecules and atoms) are not locked together and can move past each other. |
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Pressure increases with depth and
decrease at higher elevations
or altitudes This is because of the weight of the fluid above. In space, there is no pressure. It is a vacuum. |
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Pressure in fluids are transmitted
or distributed in all
directions. Because the fluids in our body have the same pressure, we are not crushed by air pressure or water pressure in the ocean. |
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Pascal’s
principle states that when a force is applied to a
confined fluid (liquid) an increase in pressure is
transmitted
equally to all parts of the fluid. |
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Force pump is a device that causes a fluid to move from one place to another by increasing the pressure in the fluid. Lungs and hearts works because fluids move from areas of higher pressure to areas of lower pressure. Because blood does not leak out of the system, it is called a closed system. |
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A hydraulic
system multiplies a force by
applying the force to a smaller surface area. It usually uses oil or water, fluids that do not lose force when compressed. Systems that use air, like air brakes or air nailers are called pneumatic systems. (i.e. your foot on a brake pedal can stop a truck) Pistons or plungers are the devices at the ends of some hydraulic systems that transmit force outside of the system hydro- Greek root for water |
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Density is the
amount of matter in a given space. |
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Buoyant force:
The upward force exerted by a fluid on a submerged object that is less
dense. The property of an object to float or sink is called buoyancy. |
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Archimedes' Principle states that the upward buoyant force exerted on a body immersed in a fluid is equal to the weight of the fluid the body displaces. |
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Scientists Blaise Pascal,(1623-1662) French mathemetician and religious philosopher whose interest in the mercury barometer led him to climb mountains and experiment with pressure. He invented mechanical adding machines that predicted computers. Daniel Bernoulli (1700-1782) Swiss mathematician whosework with moving fluids is the basis of today's work with airplanes, submarines, water systems, and hydraulics. |
B01 Heat |
Picture | Core Knowledge or Concept |
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Temperature
is a measure of the average kinetic energy of the individual particles (i.e. two units of temperature are degrees Fahrenheit (°F) and degrees Celsius (°C). absolute zero is the lowest temperature possible. atoms stop moving. |
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Thermal
energy is the total energy of all of the particles in a system. |
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Heat is thermal energy moving from warmer objects to cooler objects. |
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Heat is
transferred (moved) in three ways: a. Conduction - the process of heat being transferred from one particle of matter to another without the movement of matter itself. (i.e. by touch) |
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b. Convection
- the movement that transfers heat by the movement of currents within a
fluid. (i.e. a fire’s heat rises & warms the air above, cool air falls) |
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c. Radiation
- the transfer of energy by the electromagnetic waves. (i.e. heat from a fire warms your hands and face from a distance) |
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Conductors
are materials that conduct
energy well. (i.e. metal pot handles, copper wire) |
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Insulators are materials that do not
conduct energy well. (i.e. pot holders, plastic coating on wires) |
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The
states of matter are:
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B02 Atoms |
Picture | Core Knowledge or Concept |
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An
atom is the smallest particle of a
substance (matter). |
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There are 2 regions of an atom The nucleus in the tiny center of the atom is made of protons and neutrons. The electron cloud is the outside area made up of mostly empty space. |
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Protons
are tiny positively charged
particles. Neutrons are neutral (no charge). |
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Atomic mass
is the total number of an atom’s protons and neutrons. Atomic number is the number of an atom’s protons only. This number is used to classify types of atoms. |
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Electrons
are negatively charged
particles that orbit around the nucleus in the electron cloud. They are
much smaller than protons and neutrons. In a neutral atom, there are the same number of electrons as protons. Valence electrons react with other atoms. Thry have the most energy and are the furthest from the nucleus. |
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A pure substance is stuff made of only one kind of matter with definite properties. (i.e. sugar, salt, iron, & copper) |
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Some pure substances, called elements, cannot be broken down into other substances by any chemical means. (i.e. iron, copper, gold, carbon, & chlorine) |
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The periodic table an arrangement of the chemical elements by increasing atomic number, which displays the elements so that one may see trends in their properties. |
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Elements in the same group (column) react
similarly. Group1 and 2 metals react strongly with group 7 elements. Group 8 gasses are unreactive. |
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Scientist MarieCurie (ne: Sklodowska): the first person to receive 2 Nobel Prizes for her work in radioactive particle physics (1903) and chemistry (1911). Her work paved the way for modern nuclear technologies in medicine, power, and the military. |
B03 Matter and Molecules |
Picture | Core Knowledge or Concept |
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A
molecule
is a group of atoms that are joined together and act as a single unit. (i.e. a water molecule is made of 2 hydrogen atoms tied to 1 oxygen atom: H2O.) |
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A chemical
formula (molecular formula) is the recipe for what is in a molecule. The element symbol Letter goes before the Number of atoms, so H20 has 2 hydrogen & 1oxygen. A structural formula is a way to show how molecules are put together. Lines represent bonds between atoms. |
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Atoms are held together in
chemical bonds
by sharing, gaining, or losing electrons. A compound is a substance made of two or more elements. |
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A mixture is
two or more substances found together. |
Solution is
a very well-mixed mixture of two substances that keep their properties. (i.e. sugar water vs. salt water) A solvent is a liquid and solute is a solidlike a powder. |
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Characteristic properties
are qualities of a substance that never change and can be used to identify
the substance. They can be physical properties and chemical properties. |
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Physical properties can be
any property used to
characterize
matter and energy and their interactions. They can be observable using instruments or the five senses. (i.e. crystal shape, color, texture, hardness, bends or breaks, density, resistance to water and fire, conductivity or heat or electricity, melting/boiling points) |
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Density of a
substance is its mass per unit volume. (mass / volume) |
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Physical changes change the form of a substance, but not its
identity. (i.e. crushing, folding,
freezing, boiling, dissolving, mixing, cutting, twisting ) |
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Scientist Craig Venter and Francis Collins decoded the DNA molecule of several life forms, including humans.DNA is one of the largest molecules of all and holds the instructions for how to build the molecules of living things. |
B04 Chemistry |
Picture | Core Knowledge or Concept |
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Chemical
properties are how a substance reacts and changes with other
substances under which conditions. |
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In
chemical changes
/ reactions one or more substances combine or break apart to form new
substances. (i.e. burned wood becomes charcoal, water vapor, and carbon dioxide gas) |
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Chemical
equations show the reactants and products of a reaction on either side
of an arrow showing the direction of the reaction. |
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conservation
of mass: matter is neither created nor destroyed during a chemical
reaction. A balanced chemical equation shows this by having the same number of atoms on both sides of the equation. |
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Bonds store energy that is related to thermal energy.
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Reaction rates are the speed that a
substance enters into a chemical reaction. Reactions can be controlled
using 1. concentration: how much chemical is present (the flask limits oxygen) 2. surface area: how much is exposed to the reaction (powder versus block) 3. temperature: thermal energy often speeds reactions 4. catalysts/enzymes: molecules that help the reaction 5. inhibitors: molecules that slow reactions |
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Scientist Hans Adolf Krebs- Nobel Prize winner- discovered how energy molecules are made in living cells in the citric acid or Krebs cycle. |
B05 Waves |
Picture | Core Knowledge or Concept |
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A
wave is a disturbance that
transfers energy from place to place. (i.e. jump rope) Two categories of waves are: a. Mechanical Waves- require a medium to travel through. (i.e. water waves in a pond) b. Electromagnetic Waves- do not need a medium. (i.e. light and radio waves.) A medium is a material through which a mechanical wave travels. |
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Two types of waves are: ![]() a. Transverse - waves that move the medium at right angles to the direction in which the waves are traveling. The top is a crest and the bottom is a trough. (i.e. like a snake wiggling side to side in an ‘S’ shape) |
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b.
Longitudinal
- waves move the particles of the medium parallel (the long way) to the
direction that the waves are traveling. ![]() Compression is close together and rarefaction is spread out. (i.e. like a slinky getting squeezed and then opening up) |
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Properties of waves are:![]() a. Amplitude is the maximum distance the particles of a medium move away from their resting point as a wave passes through the medium. b. Wavelength is the distance between two corresponding parts of a wave. c. Frequency is the number of complete waves that pass a given point in a certain amount of time. d. speed is the distance travelled divided by time. speed = wavelength x frequency (= distance / time) |
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Interference
between waves that meet. When two waves pass through each other they can add together to make a larger amplitude or cancel each another out |
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Scientist Jean-Baptiste Joseph Fourier (1768-1830) was a French mathematician who worked on how frequencies are related by developing the Fourier Transform/ |
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Technology Sonograms use sound waves that pass through the medium of the body to make pictures. |
B06 Sound |
Picture | Core Knowledge or Concept |
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Sound is a disturbance that travels through a
medium as a longitudinal wave. Sound begins with a vibration. Sound waves can travel in solids, liquids and gasses. |
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An echo is when sound waves reflect off of an object |
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Sound waves spread out and can
diffract or bend around objects. |
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The
loudness of a sound depends on the
amplitude or energy of its wave. Intensity is the measure of the energy of a sound wave over an area. The unit of loudness is the decibel dB. |
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Distance can make sounds
less loud. As sound waves spread out, they have less energy per unit of area, so they sound softer. |
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The
pitch of a sound depends on its
frequency. The unit of frequency is the Hertz or Hz. Humans can ususally hear from 20Hz to 20,000 Hz. |
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The speed of sound is different in different materials. Sound generally goes slower in gasses and faster in solids. Speed can change with elasticity, density, and temperature. A sonic boom is when something goes faster than mach 1, the speed of sound. |
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Doppler effect moving sound
sources can make frequencies appear higher or lower by compressing or
spreading out waves. |
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Scientist / Engineers Robert Moog manufactured early synthesizers by creating sound modules that could generate or change sound waves. |
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Technology Synthesizers are musical instruments that simulate or create the sounds of instruments by changing the shapes of sound waves. |
B07 Electromagnetic Waves |
Picture | Core Knowledge or Concept |
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Electromagnetic waves carry both electrical and magnetic energy. In a vacuum (outer space), they travel at the speed of light, 300,000km / second. Electromagnetic radiation is the energy transferred by electromagnetic waves. |
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Wave Model of Electromagnetic Waves (Light) EM waves act like transverse waves. By using polarized filters or lenses, waves that are vibrating in certain directions can be blocked like a rope waved through a picket fence. |
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Particle Model of Electromagnetic Waves (Light) A photon a tiny packet of light that acts as both a wave and a particle. They are created when electrons lose energy or when protons fuse in the sun. They can create electricity when they hit electrons in solar panels. |
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A
ray is a straight line used to
represent a light wave in diagrams and in mathematics. |
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The electromagnetic
spectrum
is the entire range of frequencies and wavelengths of electromagnetic
waves including the visible spectrum that we see as colors. (i.e. radio
waves, microwave, infrared, visible light, ultraviolet, x-rays, gamma
rays.) |
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Radio Waves: Long waves with low energy, these are used in AM/FM radios, HAM and short-wave radios, walky-talkies, baby monitors, and the like. |
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Microwaves: Shorter radio waves are called microwaves. Water in microwave ovens responds to these frequencies by vibrating and heating up. Radar systems and some communication devices use these frequencies. |
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Infrared waves Just below the visible spectrum is infrared light. It is given off by everything that radiates heat. Thermograms can pick up these heat rays, giving us a way to see in the dark using cameras that convert infrared to visible light. |
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Visible Light Red, orange, yellow, green, blue, indigo, violet and all shades between. These are the frequencies that our eyes can see. |
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Ultraviolet Rays High frequency light waves that bees and other insects can see, but humans can not. Skin responds by darkening (tans) and making vitamin D. Ultraviolet light can kill or mutate cells by breaking DNA and causing mutations. |
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X-Rays High energy rays that can penetrate soft tissues, leaving white spots on film where they were blocked by bone or other dense things. Engineers use them to find cracks in metals and cement structures. |
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Gamma Rays The most energy with the shortest wavelength & highest frequency. They are the only rays strong enough to escape some stars in large bursts. Used in medicine to kill tumors using tools like the gamma knife (left) |
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Scientist Karl G. Jansky (1905-1950) Bell Laboratories Engineer Invented Radio Astronomy when he was looking for sources of static that could interfere with the newly invented radio broadcast systems. He concluded that the biggest source of radiation was coming from the Mily Way galaxy. |
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Technology Radio Telescopes: The Atacama Large Millimeter/submillimeter Array "ALMA's test views of the Antennae show us star-forming regions on a level of detail that no other telescope on Earth or in space has attained. This capability can only get much better as ALMA nears completion," said Dr. Mark McKinnon, North American ALMA Project Manager from the NRAO in Charlottesville, Virginia. |
B08 Light Waves |
Picture | Core Knowledge or Concept |
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When
light strikes an object, the light can be
reflected, transmitted, or
absorbed. Objects can be transparent, translucent, or opaque. |
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We see most things because of the colors that are absorbed or reflected off of them. The rose reflects red and absorbs blue and green. |
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When a ray of light hits a surface it bounces off at an
equal and opposite angle. Law of reflection states that the angle of reflection is equal to the angle of incidence. In regular reflections, parallel rays reflect in parallel, giving a clear image. In diffuse reflections, rays are scattered, |
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Optics The technology of using lenses and mirrors to magnify images by bending light. A focal point is where light rays meet at a point and an object may come into focus. Its location is given as a distance from the center of a lens or mirror. |
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A mirror
is an object that reflects light.It can be shaped to change the size of an
image.It comes in three basic shapes.
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Refraction Index of refraction: Light travels at different speeds in different mediums. When a wave enters a medium at an angle, one side of the wave changes speed before the other side, causing the wave to bend or refract. This is how lenses work. |
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A
lens is a shaped object that bends
light. In can change the size of an image. The shape of the lens controls
the angle at which the light hits. Lenses comes in two basic shapes.
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Scientist Edwin Hubble (1889-1953 of Wheaton, Illinois) Used observations with light telescopes to confirm the existence of galaxies in an expanding universe.. The Hubble space telescope was named in his honor. It uses a large mirror. |
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Technology Light Telescopes: Reflecting telescopes (invented by Sir Isaac Newton ca 1668) use concave mirrors to focus animage into a lens. Refracting telescopes (first used for astronomy by Galileo Galilei in 1609) use lenses to magnify distant images.The first western telescopes appeared around 1600 in the Netherlands. |
B09 Magnetism |
Picture | Core Knowledge or Concept |
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Magnets are materials that attract iron. They can be made out of the elements iron, nickel, cobalt (and less often neodymium & samarium) Lodestones are rocks that contains the mineral magnetite. Materials with iron are called ferromagnetic. |
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Magnetic Poles are the strong ends of a magnet. They always come in North and South pairs. Opposites (N+S) attract, Same (S+S or N+N) repel. The Earth's core is a giant iron magnet making Earth's magnetosphere. |
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Magnetic
Field is the area around a magnet Arrows are drawn from the North pole to the South pole. Where the lines are densest, the force is strongest, like at the poles. |
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Combining fields Filed Lines join together when opposite poles attract. Field lines push and do not join when similar poles repel. |
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A compass is a device that points along magnetic field lines towards the north and south poles of a magnet. |
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Magnetic fields are created by
electrons spinning in the same direction. |
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Magnetic domains are areas in which the electrons spin in the same
direction. The more electrons are aligned, the stronger the field. You can make a magnetic domain by rubbing iron with one pole of a magnet to align electrons. You can mess up a magnetic domain by hitting or heating it. An electric current in a coiled wire can also align electrons, making an electromagnet |
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Scientist William Gilbert (1544-1603) wrote the book (6-volumes) called Die Magnete on electricity and magnetism setting the words used in the field ever-after. He described his own experiments and new ideas about Earth's magnetic field. |
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Technology Electric Motors use magnets and electromagnets to turn spinning sharft that can be used to make motion. |
B10 Static Electricity |
Picture | Core Knowledge or Concept |
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Electrons (-) and
protons (+) are two particles
that have equal and opposite
electrical charges. Most atoms have the same number of protons and electrons, so they have a neutral (no) charge. Electrons can break free of atoms and move to other objects, leaving a positive charge where the protons remain in place. |
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Opposite charges attract. Similar charges repel. |
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Electric
Field is the area around a charged particle where electrical force can
be exerted. Arrows are drawn from the positive charge to the negative charge. Where the lines are densest, the force is strongest, near the charge. |
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Combining fields Filed Lines join together when opposite charges attract. Field lines push and do not join when similar charges repel. |
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Static electricity
is the buildup of charges on an object. Electrons build up in fast moving
air and water droplets during a thunderstorm. Static discharge is the loss of charge. Charges move between two objects until their charges are equal. Lightning is a huge spark that balances a buildup of electrons in the atmosphere. |
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The law of conservation of charge states that charges are
neither created nor destroyed. If an object gives up electrons (hair), another object gains those electrons (the balloon.) . |
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An
electroscope
is a device that can be used to detect a static charge. A charge is
induced in the light leaves that repel each other and split apart. This picture shows how to build one with foil and an aluminum can. |
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Static charges can build up
in 3 ways, friction,
conduction, and
induction. Charging by friction is the transfer of electrons from one uncharged object to another by rubbing. |
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Charging by
conduction is the transfer of electrons from a charge object to
another by direct contact. |
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Charging by induction is movement of electrons to one part of an object that is caused by the electric field of a second object. The electric field around the charged object attracts or repels electrons in the second object. |
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Electrochemical cells (aka
batteries) store chemical energy and change it into the energy of
static electric charges. |
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Scientist John Clerk Maxwell (1831-1879) developed our unified theory of electricity and magnetism, thus becoming the father of modern physics. |
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Technology Lithium Ion batteries are the new high-energy technology being developed at places like Argonne National Laboratories in Lemont Illinois for use in electric cars and other vehicles. |
B11 Electric Current & Circuits |
Picture | Core Knowledge or Concept |
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Electric current is the continuous flow of electrons (note: a spark is
not continuous.) The amount of charges per second is measured in amperes (amps or A). |
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An
electric circuit is
a closed
(complete) path that allows current to flow. An open circuit (switch is open) stops the flow of electrons. |
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A resistor
or semiconductor
is a material like silicon, germanium, or arsenic (used in computer chips)
that lose or use electrical energy, slowing the flow. |
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A
device is anything that uses or
resists the flow of electrons. Devices include resistors, buzzers, and
light bulbs. They are represented as resistors in a circuit. |
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Conductors
are materials that allow electrons (red) to flow like metal wires. A
conductor transfers electric charge well, but electric charges do not flow
easily through every material. |
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Source: Charges in an electric circuit flow because of a difference in electrical potential energy called voltage, measured in volts (V). You can think of voltage as the amount of force pushing an electric current. A voltage source is a device that creates a potential difference in an electric circuit. |
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Resistance
is the measure of how difficult it is for charges to flow through a
material. The greater the resistance, the less current there is for a
given voltage. The unit of measure of resistance is the
ohm (Ω). Resistance can vary
with:
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If all parts of an
electric circuit are connected one after another along one path, the
circuit is called a series circuit. In a
series circuit, there is only one path for the current to take.
Because of this, if one light goes out in a series circuit, the other
lights will go out. Adding lights to a series circuit will make other
lights in the circuit dimmer. |
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In a
parallel circuit, there are several paths (called
branches) for current to take. If one light goes out in a parallel
circuit, the other lights in the circuit will remain lit because there is
still current in the other branches. When branches are added to a parallel
circuit, the overall resistance actually decreases because the current has
more paths to follow. |
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A multimeter includes
each of these functions. |
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A
circuit diagram
shows the sources, conductors, and devices (as resistors) using symbols |
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Scientist Paul and Joseph Galvin, founders of Schaumburg Illinois based Motorola along with son Paul, developed the car radio and the germanium based transistor in 1955. |
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Technology The Transistor (1955) was the first mass-produced semiconductor, the forerunner of today's microprocessors at the heart of telephones, TVs, and almost all electronic devices. Transistors allowed early miniaturization of low-power electronics. The older vacuum tubes used to break,burn out, use alot of electricity, and alot of space. |
B12 Electromagnets & Motors |
Picture | Core Knowledge or Concept |
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Whenever electrons flow , they generate a magnetic field that wraps around
the direction of the current. If you move a magnet near a coil of wire, a electrons begin to flow in the circuit. This relationship is know as electromagnetism. |
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A solenoid is a coil of wire that increases the electromagnetic effect. The ends of the coil become the north and south poles of the magnetic field. |
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A solenoid's
magnetic field has three properties.
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Adding a
ferromagnetic material inside the coil creates an
electromagnet. An electromagnet can be made stronger by:
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When a current-carrying
wire is placed in a magnetic field, electrical energy is converted into mechanical energy. |
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Moving a magnetic field
near a solenoid generates
an electrical current. |
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An electric motor is a device that uses an electric current to turn an axle. An electric motor converts electrical energy into mechanical energy. |
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Scientist Samuel Morse (1791-1872) inventor who improved the telegraph and developed a binary communications method (Morse Code) that is the basis of digital communications today (digital computers& media.) |
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Technology![]() The telegraph was the 'father' of modern telephones & computers today. It used electro - magnets to communicate 'dots and dashes' over thousands of miles acrossf oceans before wireless radios. |