September/October 2017 – Vol. 30 No. 1

President’s Pick: Cloud in a Bottle

Posted: Monday, August 1st, 2011

by Rick Pomeroy

Purpose: The purpose of this activity is to model cloud formation in a 2 liter clear, colorless soda bottle through the process of adiabatic cooling.

Content: Clouds form in the atmosphere when the amount of water vapor that the air can hold exceeds the capacity.  When the capacity of the air to hold the water is exceeded, water molecules condense on small particles to form clouds.  Various factors affect the capacity of the air, primarily temperature and pressure. Most people have witnessed the condensation of water vapor due to drops in temperature (fog on car windows is an example) however few ever realize that as pressure drops, the capacity of the air to hold water in vapor form decreases.  This factor accounts for the formation of summer thunder head clouds near mountains.
For instance, in July when warm moist air from the Sacramento Valley rises over the Sierra Nevada, it condenses into ice crystals that appear as clouds.  This is largely due to the decreased pressures at high elevations as well as cooling.


2 liter soda bottle- clear, colorless, with label removed plus cap

Matches, incense, or chalk dust (source of dust or smoke)

Warm water (30 ml per bottle) water does not have to be hot.


  1. Put small amount of warm water in the 2 liter bottle (it should barely cover the bottom)
  2. Attach the cap and shake or swirl the bottle to encourage the spread of water vapor throughout the inside.
  3. Strike a match (Incense can be used instead of burning matches)
  4. Remove the cap, blow out the match and drop the extinguished match into the bottle so that some of the smoke enters the bottle at the same time. (chalk dust can be used instead of matches)
  5. Attach the cap firmly
  6. Squeeze the bottle then release quickly so that you hear a pop sound.
  7. Repeat this step several times.
  8. Look inside the bottle and watch for fog to form when the squeeze is released.
  9. It might be helpful to shine a flashlight through the bottle to facilitate seeing the cloud.


  1. What is the purpose of the smoke or chalk dust?
  2. What would happen if you tried this without the smoke/dust?
  3. Where have you seen  cloud formation caused by decreases in pressure besides in your bottle and over mountains in the summer?

Rick Pomeroy is science education lecturer/supervisor in the School of Education, University of California, Davis and is CSTA’s president.

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Written by Rick Pomeroy

Rick Pomeroy

Rick Pomeroy is science education lecturer/supervisor in the School of Education, University of California Davis and is a past-president of CSTA.

2 Responses

  1. A great meteorology activity. I have done it with a bicycle pump and a stopper to build up pressure and then quickly release it.

  2. This is really cool! I will use the idea when demonstrating changes of state (from liquid to a gas).

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State Schools Chief Tom Torlakson Announces 2017 Finalists for Presidential Awards for Excellence in Mathematics and Science Teaching

Posted: Wednesday, September 20th, 2017

SACRAMENTO—State Superintendent of Public Instruction Tom Torlakson today nominated eight exceptional secondary mathematics and science teachers as California finalists for the 2017 Presidential Awards for Excellence in Mathematics and Science Teaching (PAEMST).

“These teachers are dedicated and accomplished individuals whose innovative teaching styles prepare our students for 21st century careers and college and develop them into the designers and inventors of the future,” Torlakson said. “They rank among the finest in their profession and also serve as wonderful mentors and role models.”

The California Department of Education (CDE) partners annually with the California Science Teachers Association and the California Mathematics Council to recruit and select nominees for the PAEMST program—the highest recognition in the nation for a mathematics or science teacher. The Science Finalists will be recognized at the CSTA Awards Luncheon on Saturday, October 14, 2017. Learn More…

Written by California Science Teachers Association

California Science Teachers Association

CSTA represents science educators statewide—in every science discipline at every grade level, Kindergarten through University.

Thriving in a Time of Change

Posted: Wednesday, September 13th, 2017

by Jill Grace

By the time this message is posted online, most schools across California will have been in session for at least a month (if not longer, and hat tip to that bunch!). Long enough to get a good sense of who the kids in your classroom are and to get into that groove and momentum of the daily flow of teaching. It’s also very likely that for many of you who weren’t a part of a large grant initiative or in a district that set wheels in motion sooner, this is the first year you will really try to shift instruction to align to the Next Generation Science Standards (NGSS). I’m not going to lie to you, it’s a challenging year – change is hard. Change is even harder when there’s not a playbook to go by.  But as someone who has had the very great privilege of walking alongside teachers going through that change for the past two years and being able to glimpse at what this looks like for different demographics across that state, there are three things I hope you will hold on to. These are things I have come to learn will overshadow the challenge: a growth mindset will get you far, one is a very powerful number, and it’s about the kids. Learn More…

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Written by Jill Grace

Jill Grace

Jill Grace is a Regional Director for the K-12 Alliance and is President of CSTA.

If You Are Not Teaching Science Then You Are Not Teaching Common Core

Posted: Thursday, August 31st, 2017

by Peter A’Hearn 

“Science and Social Studies can be taught for the last half hour of the day on Fridays”

– Elementary school principal

Anyone concerned with the teaching of science in elementary school is keenly aware of the problem of time. Kids need to learn to read, and learning to read takes time, nobody disputes that. So Common Core ELA can seem like the enemy of science. This was a big concern to me as I started looking at the curriculum that my district had adopted for Common Core ELA. I’ve been through those years where teachers are learning a new curriculum, and know first-hand how a new curriculum can become the focus of attention- sucking all the air out of the room. Learn More…

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Written by Peter AHearn

Peter AHearn

Peter A’Hearn is the Region 4 Director for CSTA.

Tools for Creating NGSS Standards Based Lessons

Posted: Tuesday, August 29th, 2017

by Elizabeth Cooke

Think back on your own experiences with learning science in school. Were you required to memorize disjointed facts without understanding the concepts?

Science Education Background

In the past, science education focused on rote memorization and learning disjointed ideas. Elementary and secondary students in today’s science classes are fortunate now that science instruction has shifted from students demonstrating what they know to students demonstrating how they are able to apply their knowledge. Science education that reflects the Next Generation Science Standards challenges students to conduct investigations. As students explore phenomena and discrepant events they engage in academic discourse guided by focus questions from their teachers or student generated questions of that arise from analyzing data and creating and revising models that explain natural phenomena. Learn More…

Written by Elizabeth Cooke

Elizabeth Cooke

Elizabeth Cooke teaches TK-5 science at Markham Elementary in the Oakland Unified School District, is an NGSS Early Implementer, and is CSTA’s Secretary.

News and Happenings in CSTA’s Region 1 – Fall 2017

Posted: Tuesday, August 29th, 2017

by Marian Murphy-Shaw


This month I was fortunate enough to hear about some new topics to share with our entire region. Some of you may access the online or newsletter options, others may attend events in person that are nearer to you. Long time CSTA member and environmental science educator Mike Roa is well known to North Bay Area teachers for his volunteer work sharing events and resources. In this month’s Region 1 updates I am happy to make a few of the options Mike offers available to our region. Learn More…

Written by Marian Murphy-Shaw

Marian Murphy-Shaw

Marian Murphy-Shaw is the student services director at Siskiyou County Office of Education and is CSTA’s Region 1 Director and chair of CSTA’s Policy Committee.