Properties of water and the water cycle
cohesion and adhesion
The stickiness of water
Surface tension is the ________ across the surface of water caused by polar molecules pulling on one another
Tightness
Earth's water supply
Total amount of water on earth has not changed much since early in time The same water is cycled over and over again
Stick model
hydrogen oxygen hydrogen
Water molecule
(oxygen hydrogen hydrogen
Hydrogen
+ (positive)
Oxygen
- (negative)
How water is formed
2 hydrogen atoms join 1 oxygen atom
Cohesion
Attractive force between water molecules
Capillary action
Caused by the combined cohesive and adhesive forces between water and some other material Allows water molecules to move through materials with pores ex: water in a straw or water clinging to fabric
Explain how cohesion, adhesion, and surface tension keep the insect from falling into the water
Cohesion- stick to itself to create a film on top of the water Adhesion- the bug can stick to the water Surface tension- allows the insect to stick to the water without sinking
Surface tension
Cohesive forces among water molecules
Water cycle
Continuous process by which water moves through through bodies of water, land, and living things on earth's surface to the atmosphere and back to earth's surface Has no beginning and no end Renews the usable supply of fresh water on earth
The pulling forces the surface of water into what kind of shape
Curved shape
Water that falls on land
Evaporate, runoff into bodies of water, become ground water, or be taken up by plants and animals
Rain is always
Freshwater
Water vapor
Goes into the atmosphere Also enters the atmosphere from lakes rivers and exhaling animals
Chemical formula of water
H O 2
Water has what kind of specific heat
High
Solid form of water
Ice Molecules are tightly packed
Solid ice
Less dense than liquid water due to hydrogen bonds
Solution
Mixture that forms when one substance dissolves another
Pores
Narrow spaces
Adhesion
Occurs when water molecules are attracted to other substances ex:water on cloth or water on glass
Where most evaporation takes place
Over the ocean The salt does not get enough energy to become gas so it doesn't evaporate
A molecule that has electrical charge
Polar molecule
Runoff
Precipitation runs off the surface and flows downhill into streams These flow into larger streams then rivers and eventually back to the atmosphere
Evaporation
Process by which molecules of liquid water absorb enough energy to change to the gas state
Infiltration
Process where rain water soaks into the ground through the soil and under ground rock layers Some of this water returns to the surface at springs or in low spots downhill
States of matter
Solid - Liquid - Gas (Melting) (Evaporation)
Why solids sink
Solids are more dense than other liquids
Precipitation
Source of all fresh water on earth Water that falls to the ground as rain snow hail or sleet Most precipitation falls into the ocean
Hydrogen molecules attract oxygen molecules and as a result they...
Stick together
Solvent
Substance that does the dissolving
What the water cycle is driven by
Sun
Liquid form of wayer
Water Molecules are loosely packed and move fast
Universal solvent
Water because it dissolves more substances than any other solvent
Transpiration
Water that enters the atmosphere (evaporates) from plants As plants absorb water from the soil the water moves form the roots through the stems to the leaves adding to the amount of water vapor in the air
Groundwater
Water that remains under ground As the water infiltrates through the soil and rock layers many of the impurities in the water are filtered out
Gas form of water
Water vapor Molecules move freely and very quickly
How clouds form
Water vapor cools as it rises through the air When it reaches the dew point it will condense into liquid water and clump together around dust particles
Specific heat
Water's ability to absorb and store heat or the amount of heat needed to increase the temperature of a certain mass of a substance by 1 degree
Examples of solvent
When you make lemonade from a powdered mix
Precipitation and evaporation
Worldwide amounts are balanced