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Physical Science CRCT 1 by md820pSH

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									 CRCT
Practice
S8P1. Students
will examine the
scientific view of
the nature of
matter.
   a. Distinguish
between atoms and
    molecules.
Atoms – are the basic
building block of all matter.

Each kind of atom is an
element – a pure substance
that cannot be broken down
into simpler substances.
There are 117 confirmed
elements. 90 of these
are found in nature and
the rest are synthetic
(man made)
         Location Charge   Mass

Proton   Nucleus    +      1 amu


Neutron Nucleus     0      1 amu


Electron Electron   -       Less
          Cloud            than 1
                            amu
Atomic Number – describes
the number of protons in
the nucleus of the atom.

      Mass – equal to the
Atomic
number of protons plus the
number of neutrons in the
atom.
NeutralAtom – occurs
 when electrons equal
 protons.
Amolecule is the smallest
unit of a compound that
has all the properties of
the compound.
Asubscript is a small
number that tells you
the number of atoms of
each element in the
substance.
b. Describe the difference
between pure substances
      (elements and
    compounds) and
         mixtures.
An element is an pure
 substance that cannot be
 broken down into simpler
 substances by ordinary
 chemical means.
Compounds are pure
 substances that are created
 when atoms are chemically
 combined.
Mixtures form   when two or
 more substances combine
 without joining together
 chemically.
Heterogeneous mixtures –
 look different throughout
Homogeneous mixtures –
 look the same throughout
c. Describe the movement
   of particles in solids,
    liquids, gases, and
      plasmas states.
Astate of matter is the
physical form in which
matter exists.
A  solid is a substance with
  definite shape and

   volume
  Particles are densely

   packed
  Energy binding the

   particles is very strong
A  liquid is a substance that
  Has no definite shape

  Has definite volume

  Particles are less densely

   packed and can flow around
   each other
  Energy binding the particles

   is strong
A  gas is a substance that has
  NO definite shape

  No definite volume

  The particle arrangement is

   far apart
  The binding energy is very

   weak.
Plasma is  a state of matter
 that forms when
 temperatures are high
 enough to remove
 electrons from their atoms.
  d. Distinguish between
  physical and chemical
  properties of matter as
   physical (i.e., density,
melting point, boiling point)
or chemical (i.e., reactivity,
      combustibility).
Physical  Properties are
 characteristics that can be
 observed or measured
 without changing the identity.
Chemical   Properties are
characteristics that
describes how a substance
will interact with other
substances during a
chemical reaction.
e. Distinguish between
 changes in matter as
 physical (i.e., physical
 change) or chemical
 (development of a gas,
 formation of precipitate,
 and change in color).
Physical  Change – alters the
 physical properties of a
 substance without changing
 the identity of the substance.
Chemical Change     – occurs
 when a substance is changed
 into a new substance with
 different properties.
f.Recognize that there are
 more than 100 elements
 and some have similar
 properties as shown on the
 Periodic Table of
 Elements.
The periodic table is a
chart that organizes the
information about all of the
known elements according
to their properties.
Periods– Horizontal Rows (7)
Groups – Vertical Columns
 (18)
Elements in   the same
 group have similar
 properties.
These properties are a
 result of their identical
 valence electron numbers.
Reactivity – describes how
 likely an element is to form
 bonds with other elements.
 Most chemically active are
  group 1 elements. (Due to
  their 1 valence electron)
 Group 18 (Noble Gases)

  are inert. This means they
  cannot not form bonds with
  other elements because
  they are chemically stable.
Elements on   the left are
 metals (except H)
Elements on the right are
 nonmetals
Elements along the stair
 step line are metalloids
g.Identify and
 demonstrate the Law of
 Conservation of Matter.
The  law of conservation of
 matter states that during a
 chemical reaction, matter
 cannot be created or
 destroyed.
Mass of the reactant
 equals the mass of the
 product
Acoefficient is a number
that can show how many
molecules of a compound
are present.
S8P2. Students will
be familiar with the
     forms and
transformations of
       energy.
      a. Explain energy
transformation in terms of the
   Law of Conservation of
           Energy.
Law of Conservation of
Energy – Energy is not
created or destroyed but can
be transferred.
Examples   of Energy
Transformations:
 Plants convert

  electromagnetic energy from
  the sun into chemical energy
  through photosynthesis
   Eating vegetables allows
    your body to convert
    stored chemical energy
    into thermal energy to
    maintain body temp and
    mechanical to allow you to
    move
   The sun converts nuclear
    energy into
    electromagnetic and
    thermal energy
b. Explain the
 relationship between
 potential and kinetic
 energy.
Kinetic energy – the energy
 of “motion”
Depends on mass and
 velocity
Greater the mass; Greater the
 KE
Greater the velocity; Greater
 the KE
Potential energy – stored
 energy
Ex.
    Chemical Potential – energy
 stored in chemical bonds
Elastic Potential – energy
stored in stretched or
spring objects

  Gravitational Potential –
energy stored in objects
above Earth’s surface
c. Compare and contrast the
 different forms of energy
 (heat, light, electricity,
 mechanical motion, sound)
 and their characteristics.
Each form    of energy has its
 own characteristics.
  Mechanical – Associated

   with energy of motion
   (kinetic).
  Thermal Energy – total

   amount of energy in all the
   particles
   Heat – thermal energy
    that’s transferred from
    high to low temperature

   Chemical Energy –
    energy stored in chemical
    bonds
 Electrical Energy – energy
  that results from moving
  charges
 Electromagnetic – energy

  resulting from the motion of
  atoms
    •Light, X-rays, Microwaves,
     UV
   Sound Energy – energy
    given off by a vibrating object

   Nuclear Energy – energy
    stored in the nucleus of an
    atom
     •Released through Fission
      and Fusion
d. Describe how heat can be
 transferred through matter
 by the collisions of atoms
 (conduction) or through
 space (radiation). In a
 liquid or gas, currents will
 facilitate the transfer of
 heat (convection).
Temperature is  the measure
 of the average kinetic energy
 of particles.
Heat  is the transfer of
thermal energy between
objects at different
temperatures
  Flows from higher

   temperature to lower
   temperature
Heat can be transferred
through matter in all three
phases and can be
transferred through a
vacuum (empty space).
 Conduction – Heat is
  transferred through solids
  and liquids by direct contact
  of the particles.
 Convection – Heat is

  transferred through fluids
  (liquids and gases) by
  currents.
   Radiation – transfer of
    heat without matter –
    uses electromagnetic
    waves.
   S8P3. Students will
 investigate relationship
between force, mass, and
  the motion of objects.
    a. Determine the
  relationship between
velocity and acceleration.
Force – a push or a pull
 sometimes resulting in motion.
Reference    Point – a generally
 stationary point such as a
 tree, or street sign that allows
 you to define the motion of an
 object in terms of speed,
 position, and direction.
Speed   – how fast the object
 moves.
Speed = distance / time
Units – m/s
Distance/Time Graph:
  Distance on the Y-axis

  Time on the X-axis
Velocity  – speed of
 the object in a given
 direction.
Velocity changes
 when the speed or the
 direction of an object
 changes.
Acceleration –  the rate at
 which velocity changes.
Acceleration changes if the
 speed or its direction changes.
Formula:
  a = vf – vi

           t
 Units – m/s/s
 b. Demonstrate the
effect of balanced and
unbalanced forces on
 an object in terms of
  gravity, inertia, and
        friction.
Net Force – the sum
of the forces acting on
an object.
Balanced  Forces –
 equal forces acting in

  opposite direction
 Net force equals zero
Unbalanced     Forces
  Net force is greater than

   zero
  Object moves in the

   direction of the greater
   force
  Can cause a change in

   the motion of an object
Inertia – an object’s
 resistance to a change
 in motion.
   Greater Mass –

    Greater Inertia
        – the force that
Friction
 opposes the motion of an
 object

  Static – no motion
  Sliding – objects sliding

   past each other
 Rolling – objects rolling
  past each other
 Fluid – friction from a

  liquid or gas
Gravity – force of attraction
 between all objects.
  Depends on Mass and

   Distance
  c. Demonstrate the
    effect of simple
   machines (lever,
inclined plane, pulley,
  wedge, screw, and
  wheel and axle) on
         work.
Work –   when a force is applied
 to an object and the object
 moves in the direction of the
 force.
W = F x d
   Only occurs when the object

    moves in the direction of the
    force
Machines   – makes work
easier by:
Multiplying effort force

Changing direction of

 force
Increasing Distance
6  Simple Machine
  Levers

  Pulleys

  Wheel and Axle

  Inclined Plane

  Wedges

  Screws
Lever – a bar that is free to
pivot about a fixed point
 Force Applied – Effort

  Force
 Resistance – Load




 3 classes of Levers
Pulley  – a rope or chain
 wrapped around a wheel
  Makes work easier by

   changing direction of the
   force
  Block and Tackle pulleys

   multiply effort force
Wheel and  Axle – consists
of two wheels of different
sizes.
 Larger – Wheel

 Smaller – Axle

 Makes work easier by

  increasing the effort force
Incline Plane – a
 straight, slanted surface
 Makes work easier

  allowing you to use
  less effort over a
  greater distance
Wedges     – an inclined
plane that is wider or
thicker at one end than
the other
  Makes work easier by

   changing the direction of
   the effort force
Screw  – an inclined
plane that is wrapped
around a cylinder
Makes work easier by

 increasing the number
 the threads
S8P4. Students will
 explore the wave
nature of sound and
  electromagnetic
     radiation.
    a. Identify the
  characteristics of
electromagnetic and
 mechanical waves.
Wave   – any disturbance
that transfers energy
through matter or space.

Medium  – the material
through which waves can
travel
Mechanical Wave -    a wave
 that needs a medium
Transverse Wave – a wave
 that transfers energy in a
 direction that is perpendicular
 to its medium.
Longitudinal Wave –particles
 move back and forth.
ElectromagneticWave
– A wave that doesn’t
need a medium through
which to travel
  b. Describe how the
behavior of light waves
is manipulated causing
  reflection, refraction
     diffraction, and
       absorption.
When   a wave hits an
obstacle, passes from
one medium to another,
or hits another wave, it
is possible that it will
change speed, direction,
or shape.
Reflection  – occurs when
a wave bounces back after
striking a barrier.
 Sound Reflection = Echo

 Light Reflection in mirror

  allows you to see yourself
Refraction    - the bending of a
 wave as it passes at an angle
 from one medium to another.
   Light Refracts (bends)

    •Enters a lens
    •Enters a prism
    •Enters water from air (bent
     pencil)
Diffraction     – refers to the
 bending, spreading, and
 interference of waves when
 thy go through a narrow
 opening.
   When waves pass through a

    slit, a pattern of ripples forms
    in all directions
Interference   – when two
waves collide
 Constructive – crest hits

  crest
 Destructive – trough

  hits trough
Transmission     – passing
of waves through a
medium
 Transparent– most of

  light transmits through
  the material
   •Windows, Plastic Wrap
Absorption  -
disappearance of an EM
wave into a medium
 Opposite of Reflection
   You see different colors
    due to reflection and
    absorption
    •An apple looks red b/c
     all colors but red are
     absorbed and red is
     reflected back to your
     eye
  c. Explain how the
   human eye sees
 objects and colors in
terms of wavelengths.
Your  ability to see
involves the reflection
of light.
The  Eye
  Cornea – transparent

   material helps move light into
   the eye
  Pupil – small hole that

   adjusts size in order to
   control amount of light
   entering
 Lens – responsible for
  focusing light
 Retina – where the light rays

  focus the image
 Optic Nerve – relays

  information about image to
  brain
Electromagnetic Spectrum    –
 collection of all EM frequencies
  Radio waves – longest

   wavelength, lowest frequency
   •Used in AM & FM
    broadcasting
 Microwaves – More energy
  than radio waves.
   •Radar
 Infrared Light – associated

  with heat.
   Visible Light – only part of
    spectrum that you can see
     •Longest Wavelength is Red
     •Shortest Wavelength is
      Violet
     •You see color because of
      the way light interacts with
      an object.
   Ultraviolet Light – have a
    higher frequency than
    visible light
    •Can cause reactions: tan
     the skin, too much may
     lead to skin cancer
 X-rays – can travel through
  soft tissue, such as skin, but
  not through hard bone.
 Gamma Rays – have the

  shortest waves and highest
  frequencies
   •Most Energy on Spectrum
d. Describe how the
behavior of waves is
affected by medium
 (such as air, water,
       solids).
Inorder to see any object, it
 must give off light.

    Luminous – objects that
     emit their own light
   Illuminated – objects that
    reflect light to your eyes
     •Amount of reflected light
      depends on the surface.
      (Smooth reflects more
      light than rough
      surfaces.)
Law  of Reflection – the
angle at which any wave
strikes a reflecting
surface is equal to the
angle at which the wave
is reflected
Transparent    – material that
 permits light to pass through
Translucent – material
 transmits some light
Opaque – allow no light to
 pass through
   (Wood, Carpet)
   e. Relate the
properties of sound
    to everyday
   experiences.
Sound  is a form of energy
produced by vibrating
objects.
 Mechanical Wave (needs

  a medium)
 Longitudinal Wave

  (moves back and forth)
Pitch  – highness or
 lowness of a sound
Frequency – number of
 waves that pass a fixed
 point in a given time
 period
Human Ear
  Outer – collects sounds
  Middle – transfers energy

   into inner ear by vibrating the
   3 small bones
  Inner – cochlea stimulates

   nerve cells and sends signal
   to auditory nerve.
Doppler   Effect – change in
 the frequency of a sound
 due to a moving sound
 source or a moving listener
Resonance – ability of
 objects to pick up the
 frequency of a nearby
 object
 f. Diagram the parts
    of the wave and
explain how the parts
    are affected by
changes in amplitude
        and pitch.
Amplitude   – is a
measure of wave energy.
Height of the wave
Wavelength –    the distance
between two successive
points on a wave
 Crest to Crest          or
 Trough to Trough

 Compression to

  Compression
 Rarefaction to Rarefaction
Frequency – the number
of waves produced in a
given amount of time
Higher Frequency =

 Shorter Wavelength
Lower Frequency =

 Longer Wavelength
Pitch  – refers to the highness
 or lowness of a sound.
  Determined by the frequency

   of the sound.
   •Low Pitch = Low Frequency
   •High Pitch = High
    Frequency
Wave Speed  – speed at
which a wave travels

    Speed = wavelength x
     frequency
   Affected by :
    •Medium through which
     wave is traveling.
      Mechanical Waves travel

       fastest through solids
      Electromagnetic Waves

       travel at the same speed
 S8P5. Students will
      recognize
  characteristics of
 gravity, electricity,
 and magnetism as
major kinds of forces
   acting in nature.
  a. Recognize that every
 object exerts gravitational
force on every other object
 and that the force exerted
  depends on how much
mass the objects have and
  how far apart they are.
Gravity   – an attractive
 force that works to pull
 objects together.
Law of Universal
 Gravitation – the force
 of gravity acts between
 all objects in the universe
Gravitational Force    depends
 on:
  Mass – amount of matter

  Distance

  Greater the Mass; Greater

   the gravitational attraction
  Closer Distance; Greater

   gravitational force
Newton’s   1stLaw of
Motion – an object in
motion stays in motion,
an object at rest stays at
rest unless an
unbalanced forces act on
it.
       – tendency of
Inertia
an object to resist a
change in its motion.
Greater Mass;

 Greater Inertia
The moon is able to
continuously orbit
Earth because the
Moon’s inertia and
Earth’s gravity are
balanced.
  b. Demonstrate the
    advantages and
disadvantages of series
and parallel circuits and
   how they transfer
        energy.
Electrical  Energy is
produced by the
movement and
distribution of charged
particles from the
atom.
Electric Current –
the flow of electric
charges.
 Unit – Ampere (A)
Potential  Difference
(aka Voltage) – results
from the differences in
electrical charges in two
locations.
 Unit = Volts (V)
Circuits – a path through
which electricity can flow.
Energy Source – “push”

 charges through circuit
 (battery – greater
 voltage; greater “push”)
   Load – operates using
    electrical energy (“light
    bulbs”)

   Conductors (Wire) –
    material that allows electrical
    energy to flow easily
Series  Circuit – a circuit
that provides one
possible path for the e- to
flow
 One bulb burn out – all

  bulbs burn out
   All loads share the
    same energy source
    •More bulbs added;
     dimmer lights get
Parallel   Circuit – offers more
 than one path for the flow of
 electricity.
   Each load has its own closed

    pathway
   If one bulb burns out; the

    others are unaffected
   Loads do not share a current.
  c. Investigate and
 explain that electric
currents and magnets
  can exert force on
      each other.
Magnetic Force     – a push or a
 pull that is exerted by a
 magnet
  Magnets have 2 poles –

   north and a south pole
  Cutting a magnet in half

   gives you two smaller
   magnets with a N & S pole.
Magnetic  Field – area
surrounding a magnet in
which the magnetic force
exists
Lines extend from one

 pole of the magnet to
 the other
Electromagnetism       –
production of a magnetic
field by an electric current
  Electric current flows

   through a coil of wire a
   magnetic field is produced
   similar to a bar magnet.
Electromagnet   –
magnet that is made by
passing an electric
current through a coil of
wire wrapped around an
iron core.
Usefulness of   electromagnets:
  Temporary – they can be

   turned off and on
  Strength of magnet can be

   increased
    •Increase strength of current
    •Add more coils
    •Increase size of core
Electric   Motor –
 transforms electrical
 energy into mechanical
Generator – transforms
 mechanical energy into
 electrical

								
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