GHSGT Review for the Physical Science Domains

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GHSGT Review for the Physical Science Domains

• Atoms, elements, bonding, compounds, mixtures,
  periodic table, Newtons Laws, Force, Work and
  Mechanical advantage, Heat transfer,
  Radioactivity, Electricity and Magnetism, Waves,
  Sound and Light

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What is Matter?

• Everything in the universe is either matter or
  energy
• Matter has mass and takes up space (volume)
• Mass is a measure of inertia
• Space L x W x H
• Either Pure substance of Elements or Compounds
  or mixtures of elements and compounds
• Element- defined by number of protons in nucleus
• Compound- two or more atoms of elements combined
  chemically (ionic or covalent)

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Pure Substances

• Elements number of protons in nucleus of the
  atom 109 metal or nonmetal
• Compounds chemically combined by loosing ()
  gaining (-) or sharing electrons Ions
• Ionic bonding electron transfer from metal ()
  to nonmetal (-) Ca² O²- CaO
• Group1 A.M.(1) Group2 A.E.M. (2)
  Group3-12 T.M.(1 to 4) Boron (3)
• Carbon (4-) Nitrogen (3-) Oxygen (2-
• Halogens (1-) Noble Gases stable octect

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Formula for Compounds

• Sum of the oxidation numbers must be O
• Cross Multiply and use subscripts to balance
• Na 1 F 1- NaF
• Ca 2 F 1- CaF2
• Na 1 O 2- Na2O
• Al 3 O 2- Al2O3

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Mixtures

• Heterogeneous can distinguish phases
• Homogeneous solute is dissolved in the solvent
  Solid, Liquid or Gas
• Colloid heterogeneous mixture where the
  different phases are held in suspension
  Tyndall Effect
• Physical Change chemical properties remain the
  same change of state
• Chemical Change chemical reaction
  rearrangement of atoms new material with new
  properties endothermic or exothermic
• Physical Properties include color, density, state
• Chemical Properties include reactivity

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Atomic Structure

• Atom smallest unit an element with
  characteristics of that element
• Nucleus and an Electron Cloud mostly empty space
• Nucleus protons and neutrons mass of the
  atom mass number of amus
• protons are the atomic number and identify the
  element
• Isotopes different number of neutrons
• Electron Cloud electrons occur at different
  energy levels filling lower levels first
  2-8-18-32 divided up into sublevels
• Outermost electrons are Valence electrons that
  are lost, gained or shared during bonding

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• Periodic Table is organized by the electron
  configuration of elements
• Groups or Families have the same number of
  valence electrons
• Each Period is filling that energy level
• ex 3 valence e- in the third energy level
• Al 3 oxidation
• another ex 2 valence e- in second
• has to be Be
• one more ex 7 valence e- in the 2

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Radioactivity

• Radioactivity spontaneous decay of unstable
  nuclei Strong and Weak nuclear forces
• Unstable because of the proton/neutron
  ratio 11 small elements 23 larger
  atom
• radioactive isotopes go through series to become
  stable releasing alpha, beta and (particles)
  and gamma (pure energy)
• Alpha decay 4amus 2p 2n He nucleus
• produces another element strong nuclear
• ex unstable U-234 undergoes alpha decay
  U-234 yields He² and Th-230

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• Beta decay high energy electron emitted from
  neutron weak nuclear force
• also changes the element by converting a neutron
  into a proton mass is the same
• ex C-14 to N-14
• Gamma does not change the identity, but does
  release energy Emc²

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What is Energy and how is
Energy used?

• Energy is the ability to cause a change or to do
  work
• 6 forms mechanical, electric, thermal,
  nuclear, radiant and chemical
• Mechanical energy is energy of motion
• Motion change of position relative to a frame
  of reference
• motion takes place at a certain speed or
  velocity
• Speed is rate of change in position ratetime
• speeddistance/time velocitydisplacement/time
  

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• speed can be constant, changing, instantaneous
  or the average is calculated
• constantstraight line curve, changing ?
  Instantaneouspoint,
  averagetotal t/dis
• Acceleration is rate of change of displacement
• Acc ?d/?t adf-di/tf-ti m/s/s or m/s²
• Acceleration is the result of an unbalanced force
• Force push or pull against a mass
• Mass measure of Inertia
• Inertia resistance to acceleration 1st Law
• Newtons Laws 1st inertia 2nd Fma
  

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• 3rd action-reaction Fma kg m/s²
  newtons of force
• friction force that opposes motion
• static rolling sliding
• lubricants push surfaces apart to reduce
  friction
• Air resistance air friction of falling objects
• all things fall at the same rate in a vacuum
  because of balance of gravity and inertia
• Gravity force of attraction(?) between all
  objects Fma Wtma Wtmg g9.8m/s²
  FgG m1m2/d²

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Work

• Work transfer or conversion of energy
• Energy has six forms and two states
• Kinetic energy energy of motion
  KE1/2mv² kg m²/s² Nm joule
• Potential energy stored energy
  PEmgh kg m/s² m Nm joule
• Conservation of energy energy can be converted
  to another form

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Power

• Power rate at which work is done or converted
  to another form
• PW/t Fd/t F/v kgm²/s²/s
  or J/s Watts hp746W
• Simple Machines multiply force or distance WFd
  make work easier
• Levers bar, wheel-axel and pulley
• Inclined Planes ramp, wedges and screws
• MA Le/Lr or Fr/Fe Eff Wo/Wi

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Momentum

• Momentum property or tendency of a moving
  object
• pmv kg m/s
• Vector magnitude and direction
• Impulse change in momentum
• Requires an unbalanced force
• Ft ?p mv f mv i

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Heat

• Heat thermal energy that moves
• Thermal Energy causes particle vibration or sum
  of internal energies
• KE increases and volume will increasethermal
  expansion
• Measured in Joules or cals 1c4.1J BTU
• Temperature measures KE of atoms
• K C F
• Tf(9/5Tc)32 Tc5/9(Tf-32) KC273

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• Heat is transferred by Conduction, Convection and
  Radiation
• Heat transfer can cause a Phase Change S-L-G
  as heat is gained
• Heating Curves plot Q vs T where the Heat of
  fusion S-L and Heat of Vaporization L-G need to
  be added for a phase change
• Heat gained or lost is calculated by
  Qm ?t Cp Cp is specific heat
• Cp low in metals high for water 4.184J/gC wow
  that is high
• measured on a calorimeter
• Insulators vs Conductors

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Electricity

• Electricity flow of electrons from pos to neg
• Form of energy that can do work
• Circuit is the path for electrons open no
  flow closed current
• Circuits have conductors (wires), source
  (battery), switch, and loads
• Current number electrons flowing or the amount
  of energy I amps
• Voltage electrical potential energy or energy
  on each electron push on electrons V volts
• Resistance opposes flow loads R ohms

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• Ohms Law V I R
• Resistors control the flow of electrons fixed
  or variable dimmer
• Electric Charge Protonpos electronneg
  opposites attract because fields fit into one
  another
• Static charge by friction and the induction
  method lightning
• Circuits are series and parallel
• Series all loads are on one path
• Parallel alternate path household
• Short Circuit path of least resistance

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• Electric Power rate at which electric energy is
  converted to other forms
• PW/t watts 1W1J/s
• PI V watts kiloWatts
• Electric Energy power x time kWh
• Cost EE x cost/kWh
• Direct current (one direction) and Alternating
  Current (60 Hz)
• Adapters convert AC to DC

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Magnetism

• Magnetism field force due to the spin of
  electrons in an aligned magnetic domains in
  permanent mag
• Electrons flowing also creates a mag field around
  the wire Right Hand Rule
• Lining up domains creates poles
  North and South cant be isolated
• Electromagnet temporary magnet has an iron core
  and wire carrying current and converts electric
  to mechanical energy
• Electric Motors electromagnet within a
  permanent magnet electric to mechanical
• Generators electromagnet in a permanent magnet
  mechanical to electrical
• Transformers step up or step down voltage to save
  power

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Waves

• Wave repeating disturbance that transfers
  energy in matter or space
• Mechanical waves transfer energy through matter
  (the medium) and can be longitudinal or
  transverse
• Electromagnetic waves are disturbances in
  electric and magnetic fields transverse
• Longitudinal waves are a series of compressions
  and rarefactions
  ex sound or seismic waves
• Transverse waves are disturbances that are at
  right angles to transfer of energy
• Crest Trough Nodes
• Wavelength distance from crest to crest

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• Amplitude wave height Energy
• Frequency number of wavelengths or cycles per
  second 1/s Hz
• Wave Speedwavelength x frequency v ? f
  m/s
• Properties include reflection, refraction,
  diffraction and interference
• Reflection change in direction from a surface
  ?i ?r mirrors
• Refraction bending rays due to change in speed
  from one medium to another slowed bends toward
  normal
• Diffraction waves bend around a barrier

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• Interference waves combine to produce another
  wave
• Constructive crests and troughs match and
  increase amplitude
• Destructive partial or complete cancellation
• Standing two waves equal in amplitude and
  wavelength from opposite directions appear not to
  move
• Resonance natural frequency an object
  vibrates when absorbs energy

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Sound

• Sound is a longitudinal wave caused by a
  vibration
• Speed of sound depends upon the temperature and
  density of the medium s?f
• increase density increase speed
• Increase temperature increase speed
• Intensity is the energy amplitude
• Loudness is how we perceive intensity decreases
  with distance measured in
  decibels-15dB whisper -150
• Pitch is how we perceive frequency
  below 20 Hz infra above 20,000 Hz ultra

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• Uses of sound include echolocation, sonar,
  ultrasonic imaging and music
• Doppler Effect apparent change in pitch due to
  change in relative position of observer or source
• ex sirens and Corvetts red shifts

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Light

• Light is a transverse wave or a disturbance in
  electric and magnetic fields
  electromagnetic
• Produced by an oscillating electron
• c 300,000,000 m/s in the vacuum of space
• Duel nature photons act as particles
  (photoelectric effect) and as waves
  (reflection,refraction,diffraction)
• Range of frequencies of the electromagnetic
  spectrum
  radio-micro-IR-visible-UV-Xrays-gamma
• Colors are ? of light ROYGBIV

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• Light is produced by incandescent, fluorescent,
  neon and by lasers
• Polarized block one plane of light
• Lasers are used to produce Holograms
• Optical Fibers total internal reflection
• Reflection by mirrors concave and convex
• Refraction by lenses convex and concave
• Images can br virtual or real, upright or
  inverted, magnified or reduced

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• GHSGT
• Wednesday
• Study!!!