8 TH Grade Integrated Science CRT Review Standards 1 (Chemistry) & 2 (Ecology)

Transcription

1 8 TH Grade Integrated Science CRT Review Standards 1 (Chemistry) & 2 (Ecology) inference = guess evidence = what is actually observed physical property = observable characteristics (color, shape, size, etc.) chemical property = how it reacts with other substances (burns, reacts with acid, etc.) physical change = does not create a new substance; same stuff (phase change; solid -> liquid -> gas) chemical change = creates a new substance (bubbles/gas, rusting, burning, color change, smoke, odor, etc.) photosynthesis plants use carbon dioxide, water, chlorophyll and sunlight to make food/sugar carbon dioxide + water + chlorophyll = glucose (sugar) + oxygen 6CO 2 + 6H 2 O + chlorophyll (sunlight) = C 6 H 12 O 6 + 6O 2 (reactants - in) (products - out) respiration produces energy from food (sugar) in animals and plants (<- at night) glucose (sugar) + oxygen = carbon dioxide + water + energy C 6 H 12 O 6 + 6O 2 = 6CO 2 + 6H 2 O + energy (reactants - in) (products - out) Law of Conservation of Mass: mass of reactants (before) = mass of products (after) a reaction (mass is neither gained nor lost) photosynthesis: light energy (sun) -> chemical energy (food) -> mechanical energy (move) or light energy -> photosynthesis -> respiration -> mechanical energy respiration: chemical energy (food) -> mechanical energy (move) plants and animals use sugar (break down sugar) to produce energy for life processes chemical energy the energy stored in food mechanical energy the energy of movement food chain flow of energy from the sun through organisms in an ecosystem sun---->grass---- >grasshopper---- >bird

2 food web interconnected food chains energy pyramid pyramid showing energy flow through trophic levels in an ecosystem *only 10% of the energy goes to the next level up (90% lost to heat energy) *if an organism is removed from a food chain/web, it affects the rest of the food chain/web producer uses sunlight to make its own food; plants consumer eats other plants and animals; animals predator hunts for its food; lion, wolf prey food caught by predators; antelope, rabbits scavenger feeds on dead organisms; vulture, hyena decomposer breaks down dead and decaying organisms; bacteria, fungi symbiosis relationship between 2 organisms mutualism both benefit e.g. flowers (pollinated) and bees (pollen/nectar), animals (CO 2 ) & plants (O 2 ) killed parasitism 1 benefits and the other (host) is harmed, but not usually e.g. tick and human, tapeworm and human, flea and dog 8 TH Grade Integrated Science CRT Review Standards 3 (Geology) & 4 (Physics) *science is used by everyone, not just scientists *early scientists/evidence helped build current ideas/theories (new evidence modify theory) *fact (most evidence) ----> theory (based on current evidence) ----> assumption (guess) *control = kept the same in an experiment *variable = what is changed in an experiment independent = what you change; dependent = what you measure

3 mineral = solid, naturally occurring, inorganic crystal with definite chemical composition e.g. talc (softest = 1), quartz, diamond (hardest = 10) *properties hardness, luster (how light reflects), texture (rough/smooth), cleavage (smooth break), fracture (jagged break) rock = made up of minerals (e.g. granite, sandstone, etc.) *igneous volcanic; cooling of molten rock; crystals (e.g. granite, obsidian, etc.) extrusive above ground; small crystals (cools fast) intrusive below ground; large crystals (cools slow) *sedimentary pieces of rock compacted & cemented (glued) together -layers (e.g. sandstone, limestone, etc.) *metamorphic changed by heat and pressure; bands (e.g. marble, gneiss, etc.) rock cycle one type of rock changing into another type of rock *igneous heating and cooling *sedimentary weathering, erosion, deposition, and cementation *metamorphic heat and pressure weathering rocks breaking down into smaller pieces (sediments) physical water, wind, ice, plant roots, etc. *weathering of rocks form soil chemical rusting, etc. erosion transport (carrying away) of sediments; usually water (#1) or wind *build on hillsides erosion is a problem (control erosion plants, retaining walls) fossil mineralized remains of a plant or animal; dies -> buried -> bones replaced by minerals *fossils are clues to past environments (e.g. shells = ocean) or climate changes *index fossils fossils to animals found in specific time periods rock layers Youngest on top and oldest on bottom (unless disturbed or intrusions) (youngest fossils on top, unless disturbed) *rocks at angle = fault/earthquake tilted them; wavy line = erosion *use fossils or radioactive/carbon dating to age rocks (same fossils = same age) *earthquakes and volcanoes bring energy from the Earth s core to surface; magma/lava (heat energy ---> mechanical energy)

4 ******************************************************************************** wave disturbance that transfers energy from place to place through a medium (water, air ) *light travels faster than sound (e.g. see lightning before you hear it) *waves travel through water, but do not carry the water with them *the more dense the medium, the faster the wave travels *energy travels out in all directions (like light from a Candle) crest - highest part of a wave trough lowest part of a wave wavelength distance from crest to crest; *shorter = more energy amplitude distance from rest position to crest or trough *bigger = louder; smaller = softer frequency - # of waves that pass a specific point in a given amount of time high frequency wave more waves pass a point; high pitch *more tightly packed; short tuning fork (high frequency = short wavelength) low frequency wave fewer waves pass a point; low pitch *more spread out; long tuning fork (low frequency = long wavelength) prism piece of glass that separates white light into all the colors of the spectrum (ROYGBIV) *different wavelengths are bent different amounts (longer = bent less) gravity force that pulls objects toward Earth (or another body) *force of gravity depends on the mass/size and distance between 2 bodies (more mass = more gravity, more distance between = less gravity) *weight (measured in newtons); mass (measured in grams or kilograms) mass amount of matter in an object; not affected by gravity weight measure of the force of gravity on an object; changes from place to place friction force when 2 surfaces rub against each other; more friction = more force needed machine device used to make work easier or more efficient; machine = less force needed *the same amount of work is done, it just takes less effort!!! *simple machine inclined plane, wedge, screw, level, wheel & axle, pulley

5 inclined plane flat, slanted surface; ramp (longer/less steep better) wedge thick at one end, thin at other; ax screw inclined plane wrapped around a cylinder; screw/jar lid lever rigid bar that rotates around a fulcrum (fixed); scissors wheel & axle 2 round objects fastened that rotate; doorknob pulley grooved wheel with rope wrapped around it; flag/blinds *complex/compound machine 2 or more simple machines; e.g. pencil sharpener mechanical advantage (M.A.) how much the machine helps you do the work (advantage) *lever with longer handle (effort arm) = better (need less force) *move fulcrum closer to weight = increase M.A. *more mechanical advantage = less effort E/R=MA Effort/Resistance=Mechanical Advantage energy = ability to do work potential energy stored energy of position (at rest); lowest at bottom & highest at top kinetic energy energy of motion; lowest at top & most at bottom ENERGY TRANSFORMATIONS mechanical energy energy of motion/movement heat/thermal energy internal energy of the particles in an object (temperature) chemical energy potential energy stored in food, matches, etc. electrical energy moving electrical charges *battery/gas burning in car = chemical energy ---> electrical or mechanical energy *blender = electrical energy ---> mechanical energy *candle burning = chemical energy ---> heat energy (& light) *smoke detector (battery) or fan = chemical energy ---> electrical energy *photosynthesis = light energy ---> chemical energy *respiration = chemical energy ---> mechanical energy HEAT TRANSFER conduction heat transfer between particles (matter doesn t move); metal spoon in hot water convection heat transfer by movement of currents within a fluid (water or air); boiling water radiation energy transfer by electromagnetic waves; heat from campfire or sun