Focus Question: What items affect evaporation rates? Water Planet Investigations 3-2 & 3-3
May 25, 2015
Focus Question: What items affect evaporation rates?
Water PlanetInvestigations 3-2 & 3-3
Drying Up Questions
What is water vapor?
Where is water vapor?
What does water vapor look like?
What happens when a wet object gets dry?
Does Location Affect Evaporation?
Where might we put the wet paper towel so it would dry quickly?
Where would it dry slowly?
How can we find out how fast water will evaporate in these locations?
Does Surface Area Affect Evaporation?
Compare size of openings for each container
Area of the water touching the air is surface area
In which container will water have the largest surface area?
In which container do you thing water will evaporate fastest?
Variables and Controlled Experiments
Anything you can change in an experiment that might affect the outcome of the experiment is a variable
A controlled experiment is an experiment in which one, and only, one variable is changed in order to find out how it affects the outcome of the experiments. All other variables are kept the same, or controlled.
Surface-Area Experiment
If you want to find out if surface area affects the amount of evaporation, how would you set up the investigation?
What variables will you control?
What variable will you change? ~
Evaporation Place Mat-4 containers
Label mat, position tray and containers
Add 25-ml of water to each container
Location Experiment
Label four cups (A, B, C, D and room/group number)
Measure 50-ml of water in each cup
Place each cup on matching letter tray
Monitor temperature twice each day
Record temperature on class chart
Location
Determine the amount of water that evaporated from each cup. Measure amount
remaining, subtract from starting amount
Use a graduated cylinder to measure volume of water
Plan procedure, then begin
Record measurements/results on Evaporation Location Charts - charts 1 and 2, answer Q1-4
Share information with Surface Area group (1-2, 3-4, 5-6, 7-8)
Complete Surface Area Chart and questions
Surface Area
Complete first two rows of chart - surface area ranking, beginning water
Measure and record amount of water remaining - begin with graduated cylinder
Calculate amount of water lost to evaporation
Order empty containers from greatest to least amount of evaporation
Compare amount of evaporation to surface area for each container - rank containers in row 5; answer Q1-2
Share information with Evaporation Location groups (1-2, 3-4, 5-6, 7-8)
Complete Evaporation Location Charts and questions
Wet Paper Towel
Describe the best way to dry a wet paper towel. Consider location and surface area in your answer.
Vocabulary Seriate
To put objects in order by one property, like the amount of water left.
Thermometer A tool used to measure
temperature.
Surface Area The area of liquid exposed to or
touching the air.
Content Where did the most evaporation happen?
Where did the least evaporation happen?
What is the relationship between temperature and evaporation?
How does surface area of a volume of water affect evaporation?
Your Questions?
Homework: Read Evaporation, pg 184-186 + answer questions. I-check 3 on Friday 1/17
Evaporation Questions
What causes evaporation?
Why does warm water evaporate faster than cold water?
How is water vapor different from liquid water?
How does temperature affect the amount of water vapor in the air?