Water on Earth The Water Cycle

Bell ringer: Where does the water on the outside of this glass come from?

Water comes from the air around the glass Water comes from the air around the glass. The air (or gas) must lose energy to change to liquid on the outside of the glass. The ice in the glass causes the air outside the glass to lose energy.

Bell Ringer When energy is added to a solid, like an ice cube, what happens? When a gas like water vapor loses energy, what happens?

The Science of the Water Cycle

Bell Ringer Draw a diagram of the water cycle in your science notebook

3 States of Water Solid – ice Gas – Water Vapor Liquid -water

1. Solid Has the least amount of energy 2. Liquid = middle or medium amount of energy 3. Gas = has the MOST amount of energy

Middleschoolchemistry.com 3 States of Water Solid- atoms packed together and vibrating very slowly Ice animation

Liquid Molecules loosely packed and sliding past each other Middleschoolchemistry.com Liquid Molecules loosely packed and sliding past each other Compare a solid and a liquid animation

Vapor (gas) Molecules are spread far apart and moving fast Middleschoolchemistry.com Vapor (gas) Molecules are spread far apart and moving fast Comparing solid, liquid, gas animation

How does water change state? By adding or removing heat energy Add energy (think Energy In) Remove energy (think Energy Exits) Heating and cooling of a solid animation Heating and cooling of a liquid melting ice animation Heating and cooling of a gas

Changing States Is energy added or removed? Ice melting- energy is ________ Water freezing- energy is _________ Water boiling- energy is __________ Adding and removing energy

Scientific terms for + or - energy Add energy= endothermic Remove energy= exothermic

Where does this “energy” come from to change the state the water is in? This process is driven by the sun and its energy

Water Cycle Water Cycle Video

What is the Water Cycle? The continuous movement of water into the air, onto land, and back into the air over and over again Water Cycle

Water Cycle- Evaporation The sun heats up liquid water and turns it into water vapor (gas) Water vapor is invisible The “smoke” we see is from the vapor condensing… Evaporation animation

Water Cycle- Transpiration Do plants sweat? Well, sort of.... people perspire (sweat) and plants transpire.  Transpiration is the process by which plants lose water out of their leaves.  Transpiration gives evaporation a bit of a hand in getting the water vapor back up into the air.

Water Cycle- Condensation Water vapor in the air gets cold and changes back into liquid, forming clouds Condensation animation

Water Cycle- Precipitation The solid or liquid water that Falls from the air to the surface -rain, snow, sleet, hail…

Water Cycle- Runoff Water that flows across land and collects in rivers, streams, and eventually the ocean

Water Cycle- Groundwater located within the rocks below the Earth’s surface

Changing states in the Water Cycle Evaporation- energy is_________ Condensation- energy is __________ Transpiration- energy is ___________

Water Everywhere! Water is MATTER. -What is matter? It has Mass and Volume.

Conservation of Matter Water cannot be created, nor destroyed. It cycles. It changes state (remember the 3 phases- solid, liquid, gas) it never decreases or increases in total amount. We do not have more or less water now than we did millions of years ago!! The Water Cycle just keeps going, and going, and going, and going……

More examples of Conservation of Matter Rock cycle Weathering/Erosion/Deposition Plate tectonics

Bell Ringer The water cycle would not occur with out: a. animals b. bacteria c. ice caps d. solar energy