Weather Lesson 2: Energy in Water

Scientist You Should Know

Dr. Karim-Aly Kassam

https://cals.cornell.edu/karim-aly-kassam

Weather impacts food!!!
Dr. Kassam works with indigenous and rural communities to remake ecological calendars so their food doesn’t disappear as the climate changes. His work includes knowledge and data from people who have deep generational understandings of their land.

Introduction to the concept

How much detail on this is important? It depends on the learner. This Plum Landing situation is fine for learners who don’t get a lot of benefit from more words.

There’s a fun little widget here:

https://www.middleschoolchemistry.com/multimedia/chapter1/lesson2

The Physics of the difference between evaporation and boiling is pretty much the concept I see as the more analytical background info for this topic. If you disagree, I absolutely encourage you to go any direction you prefer. The Water Cycle is a common place to talk about evaporation. Phases of matter would be another one. Crash Course and SciShow will have both.

Experiencing the science

The Plum Landing video has a good idea if it’s a sunny day: Go outside and paint on the pavement with water! If it’s raining, go observe puddles. Boil water on the stove or try taping a zip-top bag with a little water in it to a sunny window. We’re big terrarium/ecosystem/biodome people in my house.

Think about your wet hair drying or maybe wash the puppy and see how long it takes him to dry. What does he do to dry himself faster? Why does that work, do you think?

Convection happens in water, as well as in gas. Let’s do that in the next lesson. A very popular convection demo involves hot and cold water dyed red and blue. Google “convection current demo” and you will find several versions. Here is one:

Practice the science

Multisensory observation and response

Place bodies (hands, feet, fingers) near a puddle and think about how big it is. Go outside later and see if it’s the same. Maybe even make wet footprints to measure the size.

Outline a puddle with sidewalk chalk and then go outside and outline the new puddle.

Consider time-lapse photography.

Creative observation and response

Journal, draw, or write poetry while observing puddles on a sunny day or a pot of boiling water.

Try watercolor painting and talk about the drying of the painting. Can we change the way the painting dries and create different effects?

Why is this happening?
Rubbing alcohol and salt change the rate of evaporation, so… does that matter?

Verbal response

Journaling, explaining, writing a research paper that is well-cited… Consider the topic of droughts and what evaporation has to do with it…

Analytical observation and response

Measure stuff! Select a system like an evaporating puddle. Be all quantitative about it by making a puddle of known volume (i.e., pour 1 L of water onto the driveway). Measure time and diameter and change in diameter over time. You can collect data in the lab notebook, make a graph with time on the x-axis and puddle diameter on the y-axis. The slope will be an evaporation rate. List all the variables in the system. Measure them. Choose one to change and one to measure in response to that change. The video by Biscuit Physics talks about how evaporation is just happening on the surface of the water. Can you change the size of the surface and see if that changes the evaporation rate?