Water, Weathering, and Erosion

How many atoms is a water molecule made up of?

3

How many oxygen atoms are in a water molecule?

1

How many hydrogen atoms are in a water molecule?

2

What does the oxygen atom in water attract?

electrons

Is the oxygen end negative or positive?

negative

Is the hydrogen end negative or positive?

positive

Water is ______ because there is an equal number of e- and p+

neutral

What allows water to connect with other materials?

Hydrogen bonds

Is a hydrogen bond stronger alone or together?

together

At what temperature does water boil?

100 celcius

At what temperature does pure water freeze?

0 celcius

Why does the boiling temperature of water decrease at higher elevations?

Pressure changes

What are the properties of water?

cohesion, adhesion, high specific heat, high heat of vaporization, less dense as a solid, homeostasis

What is cohesion?

When water molecules are attracted to themselves

What causes surface tension?

cohesion

What produces a surface film on water that allows animals to walk on water?

Cohesion

What is adhesion?

Attraction to other substances

During adhesion water will make ______________________ with other surfaces such as soil, plant tissues, and cotton.

Hydrogen Bonds

What is capillary action?

When water molecules tow each other along when in a thin glass tube

What is high specific heat?

The amount of heat needed to raise or lower 1 gram of a substance by 1 degree celsius

What is high heat of vaporization?

Amount of energy needed to convert 1 gram of a substance from a liquid to a gas

What must be broken in order for water to evaporate?

Hydrogen bonds

What does water vapor form around the earth to keep it warm?

global blanket

What is less dense as a soild?

Ice is less dense as a solid than as a liquid

What is homeostasis?

Ability to maintain a steady state, despite changing conditions

On the pH scale, what is acidic?

1-6

On the pH scale, what is neutral?

7

On the pH scale, what is basic

8-14

What is evaporation?

The process where a liquid changes from its liquid state into its gaseous state

Where can water evaporate from?

Any body of water

What is transpiration?

evaporation of water from plant leaves

What is condensation?

Occurs when a gas is changed into a liquid

Condensation makes millions of tiny ______________.

Water droplets

What do the millions of water droplets suspended in the atmosphere do?

Form clouds in the sky and fog at ground level

What is precipitation?

When the temperature and atmospheric pressure is right it causes small water droplets in the clouds to form larger droplets and fall to earth.

What two places can precipitation go when it reaches earth?

Back into waterways and underground

What happens to water underground (percolation)?

Water becomes filtered by the different layers of soil and rock

What two ways do the water cycle contribute to clean water?

Percolation cleans water using Soil and Rock. Evaporation also cleans water because it only evaporates water and leaves everything else behind.

What is weathering?

The breaking down of rocks over a long period of time

What are the two types of weathering?

Mechanical (physical) and Chemical

What is mechanical weathering?

The breaking apart of rocks with temperature changes or pressure without changing their chemical composition.

What type of weathering is ice or frost wedging?

mechanical

What is ice or frost wedging?

When water seeps down into cracks, freezes and expands, forcing the rocks apart

Which type of mechanical weathering causes potholes?

ice or frost wedging

Which type of weathering is plants?

mechanical and chemical

What is mechanical weathering caused by plants?

Plants cause pressure too by wedging their roots down into the cracks of rocks. As the roots grow and expand, they can put pressure on the rocks to split.

What type of weathering is abrasion?

Mechanical (physical)

What is abrasion?

The wearing down of rocks by friction of water or wind

What is chemical weathering?

When rocks and minerals undergo changes in their composition as the result of chemical reactions.

What is the main agent of chemical weathering?

Water

What type of weathering is oxidation?

Chemical

What is oxidation?

When rocks containing iron come into contact with oxygen and water causing rust to form.

Which three elements are essential for rust to form.

Iron, oxygen, and water

What is chemical weathering caused by plants?

When naturally occurring plant acids come into contact with rock, minerals will be dissolved. This causes rock to be able to break into smaller pieces more easily.

What type of weathering is hydrolysis?

Chemical

What is hydrolysis?

When water dissolves minerals and carries them away

Which type of weathering is carbonic acid?

Chemical

How is carbonic acid formed?

When carbon dioxide dissolves into water

Carbonic acid can cause minerals to dissolve, especially those containing ____________.

calcite

Where does chemical weathering occur most rapidly?

Areas with lots of moisture and warm temperatures like topical areas.

Where does mechanical weathering occur most rapidly?

Places where there is frequent freezing and thawing like colder areas.

What is deposition?

The dropping of sediments

When do agents of erosion drop their sediments?

When their energy of motion decreases

What does erosion do?

Moves weathered sediments from one location to another.

What are the 4 agents of erosion?

Gravity, wind, running water, and glaciers

What do all of the agents of erosion have in common?

They only carry sediments when they have enough energy of motion.

What is gravity erosion?

When gravity causes materials to move down a slope.

What are the 4 types of erosion by gravity?

Creep, Slump, Earthflow/mudflow, and landslide/rockslides

What is creep erosion?(gravity agent)

When sediments slowly creep downhill due to freezing and thawing

What is slump erosion? (gravity agent)

Causes loose materials to slip down as one large mass when the material under the slumped material weakens.

What is earthflow/mudflow erosion? (gravity agent)

When heavy rain occurs, it mixes with the sediments to form a thick pasty substance that slides downhill

What is landslides/rockslides erosion? (gravity agent)

When large blocks of rock break loose from steep slopes and fall quickly to the bottom

When does landslide/rockslide erosion occur?

Earthquakes or after heavy rain

All mass movements are _________ likely to happen where there is a steep slope.

more

What do all mass movements depend on?

Gravity

What are two ways people can reduce erosion?

Plant vegetation and build retaining walls

What erodes more sediments than any other agent of erosion? Why?

Water because it usually has more energy of motion

What are the types of erosion by wind?

Creep, Saltation, and suspension

What is creep erosion by wind?

The movement of large sediments along the ground in a rolling motion

What is saltation erosion by wind?

The movement of medium-sized sediments in a bouncing motion

What is suspension erosion by wind?

The movement of smaller sediments that remain suspended in the air