Science 8 Dedrick Messana Frank Hydrology Unit. Basics you need to know… Water is essential for...
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Transcript of Science 8 Dedrick Messana Frank Hydrology Unit. Basics you need to know… Water is essential for...
Science 8Dedrick
MessanaFrank
Hydrology Unit
Basics you need to know…Water is essential for LIFEHydrosphere = all water environments on Earth
(oceans + water above ground+ water below ground + water in atmosphere)
Polar Covalent Molecule – has positive & negative end
Why is H +..and O - ?
Basics you need to know…Water is the Universal Solvent
It dissolves nutrients from rocks and soils
It dissolves gases in the atmosphereMakes nutrients and gases more
available to organisms on Earth
http://www.youtube.com/watch?v=0eNSnj4ZfZ8
Forces of AttractionCohesion =
attraction of LIKE moleculeswater molecules sticking to water molecules
Adhesion = attraction of molecules of DIFFERENT substances
water molecules sticking to molecules of another substance
Phenomena caused by ForcesSurface Tension = force on the top or
outside edge of water, holding it in a tight bubble or dropletCaused by COHESION, water
molecules want to cling to each other
Phenomena caused by ForcesCapillary Action = water moving
upward against the force of gravity in a narrow passageway, along the surface of a solid substance (hmm…where else?)
Caused by ADHESION, water molecules clinging to another substance (EX: side of a pipette, graduated cylinder, plant roots/stem, etc.)
DENSITY….very quickly….Please put the following liquids in order from the LEAST DENSE (top)…to…MOST DENSE
(bottom)!!!1)Water2)Karo Syrup3)Lamp Oil4)Honey5)Vegetable Oil6)Rubbing Alcohol7)Dawn Dish Soap
DensityD = mass / volume Density of water = 0.997 g/cubic cm (~1)
Materials LESS DENSE than water will FLOAT in water
Materials MORE DENSE than waterwill SINK in water
Substances will layer as follows:Less Dense
More Dense
Buoyancy
Force that works against gravity to allow objects to float in a liquid
Less dense materials float in more dense materials because of buoyancy
The MORE DENSE the liquid, the easier an object will float in it
The LESS DENSE the liquid, the less likely an object will float in it
Dissolving Solute in WaterDissolving a substance in water will
increase the density of the waterMore particles in the same space
Objects will be more buoyant in salt water than fresh water
Dead Sea!!
Specific HeatAmount of energy needed to raise 1 gram of
a substance by 1 degree CelsiusWater has a HIGH specific heat = heats
up and cools down SLOWLYWater is resistant to abrupt changes in
temperatureThis trait protects aquatic organisms from
temperature extremes
https://www.youtube.com/watch?v=gTqLQO3L4Ko