Clear Straws as Mini-Density Columns
Posted: Tuesday, January 1st, 2013
by Lisa Hegdahl
Even though I received this lab from my Master Teacher 22 years ago, I’ve never seen it presented at any conference or seminar I’ve attended. The lab itself is a little long for a full write up here, but with the basics, you can develop an activity to suit your needs. This lab uses the skill that we all learned as kids: picking up liquids with a straw. However, in this activity students pick up two different liquids to check relative density. In a nutshell:
- Prepare four solutions of different densities with varying amounts of saturated saltwater and tap water. One container has only saturated saltwater, one container has only water, one container has half of each, and the last container has ¼ saltwater and ¾ tap water.
- Color the liquids so they can be identified easily. (TIP: If you use yellow and blue as two of your colors, don’t use green. I use red, blue, yellow, and I leave one clear.)
- Ask students to figure out the order of the relative densities of the liquids from least dense to most dense. They do so by using their clear straw to pick up one liquid, and then a second liquid. If the liquids stack neatly on top of each other, students know that the liquid on top is less dense than the liquid below it. If the liquids mix, they know the liquids were not stacked in the correct order. Those who collect data carefully should be able to layer all four liquids in their straw.
- Students can develop their own data tables to record the results of their straw test, or teachers can create one for them.
I like this lab because the supplies are inexpensive, the activity demonstrates the intended concepts, and the students enjoy using their knowledge and investigative skills to determine the relative densities of the liquids. I’m confident your success with this activity will be as great as mine.
Posted: Wednesday, October 12th, 2016
by Jessica Sawko
In June 2016 California submitted a waiver application to discontinue using the old CST (based on 1998 standards) and conduct two years of pilot and field tests (in spring 2017 and 2018, respectively) of the new science assessment designed to support our state’s current science standards (California Next Generation Science Standards (CA-NGSS) adopted in 2013). The waiver was requested because no student scores will be provided as a part of the pilot and field tests. The CDE received a response from the U.S. Department of Education (ED) on September 30, 2016, which provides the CDE the opportunity to resubmit a revised waiver request within 60 days. The CDE will be revising the waiver request and resubmitting as ED suggested.
At its October 2016 North/South Assessment meetings CDE confirmed that there will be no administration of the old CST in the spring of 2017. (An archive of the meeting is available at http://www.cde.ca.gov/ta/tg/ai/infomeeting.asp.) Learn More…
Posted: Thursday, September 22nd, 2016
by Carol Peterson
1) To celebrate the 100th anniversary of the National Park Service, Google has put together a collection of virtual tours combining 360-degree video, panoramic photos and expert narration. It’s called “The Hidden Worlds of the National Parks” and is accessible right from the browser. You can choose from one of five different locales, including the Kenai Fjords in Alaska and Bryce Canyon in Utah, and get a guided “tour” from a local park ranger. Each one has a few virtual vistas to explore, with documentary-style voiceovers and extra media hidden behind clickable thumbnails. Ideas are included for use in classrooms. https://www.engadget.com/2016/08/25/google-offers-360-degree-tours-of-us-national-parks/. Learn More…
Posted: Thursday, September 22nd, 2016
CSTA is pleased to announce the winners of the 2016 CSTA Awards for Distinguished Contributions, Margaret Nicholson Distinguished Service Award, 2014 and 2015 PAEMST-Science recipients from California, and the 2016 California PAEMST Finalists. The following individuals and organizations will be honored during the 2016 California Science Education Conference on October 21- 23 in Palm Springs. This year’s group of awardees are truly outstanding. Please join us in congratulating them!
Margaret Nicholson Distinguished Service Award
The Margaret Nicholson Distinguished Service Award honors an individual who has made a significant contribution to science education in the state and who, through years of leadership and service, has truly made a positive impact on the quality of science teaching. This year’s recipient is John Keller, Ph.D. Dr. Keller is Associate Professor, Cal Poly San Luis Obispo and Co-Director, Center for Engineering, Science, and Mathematics Education, Cal Poly San Luis Obispo. In her letter of recommendation, SDSU science education faculty and former CSTA board member Donna Ross wrote: “He brings people together who share the desire to make a difference in the development and implementation of programs for science teaching. Examples of these projects include the Math and Science Teaching Initiative (MSTI), Noyce Scholars Program, Western Regional Noyce Initiative, and the Science Teacher and Researcher (STAR) program.” Through his work, he has had a dramatic impact on science teacher education, both preservice and in-service, in California, the region, and the country. He developed and implemented the STEM Teacher and Researcher Program which aims to produce excellent K-12 STEM teachers by providing aspiring teachers with opportunities to do authentic research while helping them translate their research experience into classroom practice. SFSU faculty member Larry Horvath said it best in his letter:“John Keller exemplifies the best aspects of a scientist, science educator, and mentor. His contributions to science education in the state of California are varied, significant, and I am sure will continue well into the future.” Learn More…
Posted: Tuesday, September 20th, 2016
by Peter A’hearn
NGSS is a big shift. Teachers need to learn new content, figure out how this whole engineering thing relates to science, and develop new unit and lesson plans. How could NGSS possibly make life easier?
The idea that NGSS could make our lives easier came to me during the California State NGSS Rollout #1 Classroom Example lesson on chromatography. I have since done this lesson with high school chemistry students and it made me think back to having my own students do chromatography. I spent lots of time preparing to make sure the experiment went well and achieved the “correct” result. I pre-prepared the solutions and organized and prepped the materials. I re-wrote and re-wrote again the procedure so there was no way a kid could get it wrong. I spent 20 minutes before the lab modeling all of the steps in class, so there was no way to do it wrong. Except that it turns out there were many. Learn More…
Posted: Tuesday, September 20th, 2016
by Robert C. Victor. Twilight sky maps by Robert D. Miller. Graph of evening planet setting times by Dr. Jeffrey L. Hunt
Our evening twilight chart for September, depicting the sky about 40 minutes after sunset from SoCal, shows brilliant Venus remaining low, creeping from W to WSW and gaining a little altitude as the month progresses. Its close encounter within 2.5° N of Spica on Sept. 18 is best seen with binoculars to catch the star low in bright twilight. The brightest stars in the evening sky are golden Arcturus descending in the west, and blue-white Vega passing just north of overhead. Look for Altair and Deneb completing the Summer Triangle with Vega. The triangle of Mars-Saturn-Antares expands as Mars seems to hold nearly stationary in SSW as the month progresses, while Saturn and Antares slink off to the SW. Learn More…