OGT Science Review

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OGT Science Review
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Physical Science
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Newtons 3 Laws of Motion

• 1st law A body at rest remains at rest and a
  body in motion remains in motion until an outside
  force acts on it (inertia)
• 2nd law A forces causes an object to accelerate
• 3rd law For every action there is an equal and
  opposite reaction

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Kinetic Energy energy in motion

• Examples jogging, an mp3 player playing music
• KE ½ mv2
• m mass
• Vvelocity

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Potential Energy stored energy

• The ability of a system to do work due to its
  position or internal structure
• Examples batteries, the food we eat, a rock on
  a ledge, an expanded rubber band
• Gravitational PE m x g x h
• M mass g gravity hheight

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Law of Conservation of Energy

• Says that energy cannot be created or
  destroyedonly converted to another type of
  energy
• Example chemical energy in food converting into
  different types of energy
• Example Solar (sun) energy converts to chemical
  energy during photosynthesis
• Example in an mp3chemical energy in a battery
  is converted into electrical energy that powers
  the mp3, which becomes sound energy

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Heat (a type of energy) can be transferred in 3
ways

• 1. conduction transfer of heat through a solid
  object
• Example heating on stove
• Convection transfer of heat by liquid or gas
• example currents in ocean waters, earths
  mantle layers, steam from water
• Radiation transfer of heat by electromagnetic
  waves
• example microwaves, x-rays, infrared

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Chemical Properties

• Any change that produces a new substance
• Examples when copper corrodes and turns green,
  when iron rusts, when something is burned

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Physical Change

• A change that does not create any new substance.
• Examples phase changes of water, cutting hair,
  creating mixture

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Endothermic reactions

• A reaction that absorbs heat from the surrounding
• Ex baking a cake

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Exothermic reactions

• A reaction that gives off heat
• Ex burning wood or paper produces heat

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Other terms in phase changes

• Freezing when a liquid becomes a solid
• Melting when a solid changes to liquid to allow
  molecules to move more freely
• Evaporation liquid becomes a gas molecules now
  moving rapidly
• Condensation gas becomes a liquid (clouds)
• Sublimation Solid directly to a gas (dry ice)
• Precipitation clouds release water in rain/snow

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Density

• Allows objects to float or sink
• Density mass/volume
• Density of water is 1 g/ml

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Atomic Structure

• Matter anything that takes up space
• Atom smallest particle of an element that has
  all the properties of that element
• Protons positive (in nucleus)
• Neutrons no charge (in nucleus)
• Electrons negative (orbit nucleus)
• Element pure substance that cannot be broken
  down into a simpler substance

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Periodic Table

• Atomic number of protons in an atom
• Hydrogen Atomic 1, so its the 1st element
• Moving left to right, the elements go up in
  atomic number on the periodic table
• Top number atomic
• Bottom number atomic mass (protons neutrons)

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Bonds

• Ionic bonds form when one or more valence
  electrons are transferred from one atom to
  another, creating positive and negative ions
• Covalent bonds some atoms complete their outer
  shell by sharing these valence electrons with
  other atoms

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Wave Properties

• Earthquake, water, and sound waves require matter
  to travel through
• Electromagnetic waves do not require matter
  (light, radio, micro, x-rays)

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• Wavelength the length of one complete
  wavelength cycle
• Amplitude a measure of the energy a wave
  carries (distance from crest to midline)
• Larger the amplitudehigher the sound
• Frequency of waves that pass a point in a
  given amount of time
• In phase when 2 waves match (become larger
  wave)
• Out of phase when 2 waves do not match up (will
  cancel each other out)

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Earth Space Science
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Big Bang Theory

• Universe was created in one giant explosion about
  13.7 billion years ago
• Galaxies are moving apart from central location
• Red shift the light most galaxies give off is
  close to the red end of the spectrumtherefore
  the light energy is longer and the color is red
  as they move out

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How a star is formed

• In space, dust gas get pulled together by
  gravity nebula
• this gravity produces heat, and nuclear fusion
  occurs
• Massive Star Cycle
• nebula-massive star-large red giant-supernova-
  black hole or neutron star
• Low mass star cycle
• nebula-star similar to sun-small red giant-white
  dwarf-black dwarf

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Tools

• Telescopes look at moons, planets, galaxies
• Spaceship allows travel to collect data
• Satellites transmit signals from outer space
• Probes sent by scientists to collect data on
  far away planets that humans cannot get to

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Galaxies

• Spiral
• Eliptical
• irregular

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Why does the earth and other planets revolve
around the sun?

• Gravitational force?

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• Earth rotates on axis causes night and day
• Earth revolves around sun
• 1 year one time around sun

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Seasons

• Hemispheres differ (summer/winter) depending on
  angle toward sun (think of the tilt?)
• Solar eclipse when moon blocks sun from the
  Earths view (moon is between)
• Lunar eclipse when Earth blocks our view of
  moon (Earth is between)

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Plate Techtonics

• Theory that the Earths crust is made up of many
  plates that are floating on top of the Earths
  mantle layer (which is molten liquid rock)
• Earthquake when plates slide past each other,
  creating friction
• Mountains when plates collide push up
• Magma comes up between 2 plates or melt through
  a soft crustal plate
• Convection currents in mantle push plates around,
  causing continents to drift and seafloors to
  spread

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Alfred Wegener

• Proposed Continental Drift Theory (at one time
  continents were all 1 land mass)
• Fossils a piece/trace of an organism that was
  once alive (found in sedimentary rock)
• Oldest rock sediments will be on the bottom

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Non-renewable resources

• Fossil fuels gasoline, oil, coal
• We can never replace or renew them
• 2 negatives
• 1. They will eventually run out
• 2. They cause global warming

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Renewable Resources

• Can be replaced and renewed
• Ex sunlight, water power, wind, wood, crops

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Global Warming

• When heat is trapped, and causes the planet to
  become warmer
• Greenhouse effect insulation layer that allows
  some heat in, and other out

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Alternative Energy Sources (VERY IMPORTANT!!)

• Wind power
• Good no CO2 produced
• Bad must have wind
• Hydroelectric (dams)
• Good no CO2 produced
• Bad need large river
• Solar panels
• Good no CO2 produced
• Bad expensive must have sun shine

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• Hydrogen power
• Good no CO2 produced large amounts of energy
• Bad explosive expensive
• Geothermal
• Good no CO2 produced
• Bad need access to underground temperatures
• Ethanol-making alcohol from corn/sugar cane
• Good produces less CO2 than fossil fuels
• Bad still creates carbon dioxide

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How can we conserve resources?

• Recycle
• Car pool
• Ride bike instead of driving
• Use public transportation
• Turn off water/electricity when not using

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Biomes

• Desert little rain large temp. change
• Rainforest hot and wet
• Tundra cold has wet/dry seasons
• Grasslands wet/dry seasons hot
• Deciduous forest (us?) even moisture warm
  summers/cold winters
• Coniferous forest moisture varies cool
  summers/cold winters

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• Biomes with colder temperatures have less
  diversity of life

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Mohs Mineral Hardness Scale

• 1 Talc (softest mineral on Earth)
• 2 Gypsum
• 3 Calcite
• 4 Fluorite
• 5 Apatite
• 6 Feldspar
• 7 Quartz
• 8 Topaz
• 9 Corundum
• 10 Diamond (hardest mineral on Earth)
• higher number will scratch lower number

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Life Science
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• Predator organisms that kill and eat others
• Prey organisms that the predators kills
• Herbivore feeds off plants only
• Carnivore feeds off animals only
• Omnivore feeds off plants and animals

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• Consumers depend other organisms for energy
• Primary consumer 1st to eat the plant
• Secondary consumer eats 1st consumer
• Producers produce own food through
  photosynthesis
• Food chain 3-5 links
• Food web network of food chains

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Energy pyramid

• Bottom is the producers (get energy from sun)
• Most available energy is located at the bottom!!
• Only 10 of each level gets passed on
• Where does the other 90 go?
• Lost as HEAT

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Biotic (living) factors

• Plants, animals, fungi, etc.

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Abiotic (non-living) factors

• Weather, rocks, water, hills, rocks, holes, etc.

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Symbiosis (aka symbiotic relationships)

• 1. mutualism both organisms benefit
• Ex bee pollinating a flower
• 2. Commensalism one benefits, other is not
  harmed OR helped
• Ex birds nest in tree
• 3. Parasitism one benefits, other is harmed
• Ex flea on dog

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Natural Selection

• When nature chooses the most favorable variation
• Those organisms that are the best for that
  environment will survive and reproduce the best?
• Ex giraffes with tall food (only tall giraffes
  survive and reproduce)

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Photosynthesis

• When plants convert light energy (sun) into
  chemical energy (glucosefood)
• Must take in carbon dioxide and release oxygen!
• Who does this? PLANTS

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Cellular Respiration

• Take in oxygen and breathe out carbon dioxide
• Who does this? ANIMALS PLANTS
• Together both cycles need each other!!
• Just opposites of each other

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Cells smallest functional unit of organism

• Eukaryotes have a nucleus and membrane-bound
  organelles
• Ex plants, animals
• Prokaryotes lack a nucleus and membrane-bound
  organelles
• Ex bacteria

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Organelles have a membrane

• Nucleus control center contains DNA
• Ribosome makes proteins
• Lysosomes digests food particles
• Mitochondriaproduces energy (powerhouse)
• Endoplasmic reticulum transports
• Golgi complex (apparatus/body) process and
  packages proteins
• Vacuole stores water food
• Cytoplasm gel-like substance that fills cell

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Plants vs. Animal Cells

• Only in plants
• Chloroplast contains chlorophyll (green
  pigment) photosynthesis occurs here
• Cell walls give plants support

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DNA

• Located on chromosomes
• Shaped like double helix
• DNA in specific spot on chromosome gene
• Viruses are not cells they must inject DNA into
  host in order to reproduce
• Ex flu and HIV

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Asexual reproduction

• Reproduction from 1 parent
• DNA is identical to parent
• Involves mitosis
• Ex bacteria, fungi, some plants/animals

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Sexual reproduction

• Involves 2 parents
• Causes VARIETY
• Involves meiosis

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Mitosis vs. Meiosis

• Mitosis cell division that produces 2 identical
  daughter cells
• Meiosis cell division that produces 4 different
  daughter cells
• Sperm/egg
• Each have 23 chromosomes
• When sperm egg 46 chromosomes

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Genetics

• Allele one form of a gene
• Dominant trait is expressed if 1 there
• Recessive only expressed if 2 present
• Homozygous same (hh, BB)
• Heterozygous different (Hh, Bb)

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Sex-linked traits

• Male XY
• Female XX
• Males are more likely to get a sex-linked
  disorder, for they only need 1 affected X to have
  the disorder. Females would need 2 affected xs
  to have the disorder (which is less likely).

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Science Technology
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2 kinds of nuclear energy

• Nuclear fusion produced inside stars
• Nuclear fission when radioactive atom called an
  isotope is broken up into two smaller atoms
• -occurs inside Earths core, nuclear power
  plants, and nuclear weapons

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Other ideas

• Know how technology and inventions impact our
  life and environment
• State advantages/disadvantages of specific
  technologies
• Examples car adv/disadv, genetically altered
  food, hydroelectric power, lasers
• How modern practices use science auditorium can
  quiet by using carpet, styrofoam, curtains
  (solid, smooth materials will reflect sound)

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Scientific InquiryScientific Ways of Knowing
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Scientific method

• Hypothesis must be able to be tested
• Dependent variable depends on independent
  variable (ex growth of plant)
• Independent variable what you are actually
  changing (ex adding fertilizer)
• Control untreated sample

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Know scientific instruments and their purposes

• Find volume of object with graduated cylinder
• Observation something you detect using your
  senses
• Inference may or may not be true based on past
  experiences

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• Deal with ethical issueswhy something is right
  or wrong
• Safety issues
• Explain yourself, no matter what your opinion?

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Much of this information in this powerpoint was
gained from http//mapleschools.com/docs/286_11_8_
2007science20study20guide09.pdf