Transcript OGT Science Review - Solon City Schools

OGT Science Review
Physical Science
Newton’s 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
Kinetic Energy: energy in motion
► Examples:
music
► KE
jogging, an mp3 player playing
= ½ mv2
 m = mass
 V=velocity
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
h=height
Law of Conservation of Energy:
► Says
that energy cannot be created or
destroyed…only 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 mp3…chemical energy in a
battery is converted into electrical energy that
powers the mp3, which becomes sound energy
Heat (a type of energy) can be
transferred in 3 ways…
1. conduction: transfer of heat through a
solid object
Example: heating on stove
2. Convection: transfer of heat by liquid or
gas
example: currents in ocean waters,
earth’s mantle layers, steam from water
3. Radiation: transfer of heat by
electromagnetic waves
example: microwaves, x-rays, infrared
Chemical Properties:
► Any
change that produces a new substance
► Examples:
when copper corrodes and turns
green, when iron rusts, when something is
burned
Physical Change:
►A
change that does not create any new
substance.
► Examples:
phase changes of water, cutting
hair, creating mixture
Endothermic reactions:
►A
reaction that absorbs heat from the
surrounding
► Ex: baking a cake
Exothermic reactions:
►A
reaction that gives off heat
► Ex: burning wood or paper produces heat
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
Density
► Allows
objects to float or sink
► Density = mass/volume
► Density of water is 1 g/ml
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
Periodic Table
► Atomic
number: # of protons in an atom
 Hydrogen: Atomic #1, so it’s 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)
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
Wave Properties
► Earthquake,
water, and sound waves
require matter to travel through
► Electromagnetic waves do not require
matter (light, radio, micro, x-rays)
► Wavelength:
the length of one complete
wavelength cycle
► Amplitude: a measure of the energy a wave
carries (distance from crest to midline)
 Larger the amplitude…higher 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)
Earth & Space Science
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 spectrum…therefore
the light energy is longer and the color is red as
they move out
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-supernovablack hole or neutron star
Low mass star cycle:
nebula-star similar to sun-small red giant-white
dwarf-black dwarf
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
Galaxies
► Spiral
► Eliptical
► irregular
Why does the earth and other
planets revolve around the sun?
► Gravitational
force
► Earth
rotates on axis: causes night and day
► Earth
revolves around sun
 1 year = one time around sun
Seasons
► Hemispheres
differ (summer/winter)
depending on angle toward sun (think of
the tilt)
► Solar eclipse: when moon blocks sun from
the Earth’s view (moon is between)
► Lunar
eclipse: when Earth blocks our view
of moon (Earth is between)
Plate Techtonics
►
Theory that the Earth’s crust is made up of many plates
that are floating on top of the Earth’s 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
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
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
Renewable Resources
► Can
be replaced and renewed
► Ex: sunlight, water power, wind, wood,
crops
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
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
► 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
How can we conserve resources?
► Recycle
► Car
pool
► Ride bike instead of driving
► Use public transportation
► Turn off water/electricity when not using
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
► Biomes
with colder temperatures have less
diversity of life
Moh’s Mineral Hardness Scale
►1
►2
►3
►4
►5
►6
►7
►8
►9
► 10
Talc (softest mineral on Earth)
Gypsum
Calcite
Fluorite
Apatite
Feldspar
Quartz
Topaz
Corundum
Diamond (hardest mineral on Earth)
**higher number will scratch lower number**
Life Science
► 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
► Consumers:
energy
depend other organisms for
 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
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
Biotic (living) factors:
► Plants,
animals, fungi, etc.
Abiotic (non-living) factors:
► Weather,
etc.
rocks, water, hills, rocks, holes,
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: bird’s nest in tree
3. Parasitism: one benefits, other is harmed
Ex: flea on dog
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)
Photosynthesis
► When
plants convert light energy (sun) into
chemical energy (glucose=food)
► Must take in carbon dioxide and release
oxygen!
► Who does this? PLANTS
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
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
Organelles: have a membrane
► Nucleus:
control center; contains DNA
► Ribosome:
makes proteins
► Lysosomes: digests food particles
► Mitochondria:produces energy
(powerhouse)
► Endoplasmic reticulum: transports
► Golgi complex (apparatus/body): process
and packages proteins
► Vacuole: stores water & food
► Cytoplasm: gel-like substance that fills cell
Plants vs. Animal Cells:
Only in plants:
► Chloroplast: contains chlorophyll (green
pigment); photosynthesis occurs here
► Cell walls: give plants support
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
Asexual reproduction:
► Reproduction
from 1 parent
► DNA is identical to parent
► Involves mitosis
► Ex: bacteria, fungi, some plants/animals
Sexual reproduction:
► Involves
2 parents
► Causes VARIETY
► Involves meiosis
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
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)
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 x’s to have the disorder (which is
less likely).
Science & Technology
2 kinds of nuclear energy
1.
2.
Nuclear fusion: produced inside stars
Nuclear fission: when radioactive atom
called an isotope is broken up into two
smaller atoms
-occurs inside Earth’s core, nuclear power plants,
and nuclear weapons
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)
Scientific Inquiry
Scientific Ways of Knowing
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
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
► Deal
with ethical issues…why something is
right or wrong
► Safety issues
► Explain yourself, no matter what your
opinion
*Much of this information in this powerpoint was gained from
http://mapleschools.com/docs/286_11_8_2007science%20study%20guide09.pdf