# OGT Science Review. Physical Science Newton’s 3 Laws of Motion: ► 1 st law: A body at rest remains at rest and a body in motion remains in motion until.

## Presentation on theme: "OGT Science Review. Physical Science Newton’s 3 Laws of Motion: ► 1 st law: A body at rest remains at rest and a body in motion remains in motion until."— Presentation transcript:

OGT Science Review

Physical Science

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

Kinetic Energy: energy in motion ► Examples: jogging, an mp3 player playing music ► KE = ½ mv 2  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 = gravityh=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 1 st 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-supernova- black 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 ► 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 CO 2 produced  Bad: must have wind Hydroelectric (dams)  Good: no CO 2 produced  Bad: need large river ► Solar panels  Good: no CO 2 produced  Bad: expensive; must have sun shine

► Hydrogen power  Good: no CO 2 produced; large amounts of energy  Bad: explosive; expensive ► Geothermal  Good: no CO 2 produced  Bad: need access to underground temperatures ► Ethanol-making alcohol from corn/sugar cane  Good: produces less CO 2 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 Talc (softest mineral on Earth) ► 2Gypsum ► 3Calcite ► 4Fluorite ► 5Apatite ► 6Feldspar ► 7Quartz ► 8Topaz ► 9Corundum ► 10Diamond (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: depend other organisms for energy  Primary consumer: 1 st to eat the plant  Secondary consumer: eats 1 st 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, rocks, water, hills, rocks, holes, etc.

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 ► 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. Nuclear fusion: produced inside stars 2. 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 ► 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

Download ppt "OGT Science Review. Physical Science Newton’s 3 Laws of Motion: ► 1 st law: A body at rest remains at rest and a body in motion remains in motion until."

Similar presentations