January/February 2018 – Vol. 31 No. 2

Density Lesson

Posted: Tuesday, September 3rd, 2013

by Jeff Orlinsky

Chemistry and physical science teachers, here is a lesson on density.  It can be used with grades 10 to 12, but with some modifications it may also work with 8th or 9th grade.  This is a modification of a lab from West Catholic High School Archdiocese of Philadelphia, with references from Kenneth E. Kolb and Doris K. Kolb, Bradley University, Peoria, IL 61625 Journal of Chemical Education.

Grades: 10 – 12

Subjects: Chemistry, Earth Sciences, Physics, Physical Science, Environmental Science

Topics: Density, polymers recycling, solution preparation.

Duration: 20 min Prep + 1 hour Activity + 1 hour Post

Setting: Classroom

Materials:

  • Appropriate glassware for mixing and sharing solutions
    • Seven (7) 250-mL beakers, graduated cylinders, stirring rod, long forceps
  • NaCl 90% Ethanol, 70% isopropanol, Karo syrup, monosodium phosphate, H2O
  • Different types of plastics (see below).
  • Hole punch

Activity:

On TV, plastics from milk, soda and other food containers are shown recycled into park benches and plastic posts. However, for some uses the recycled plastic must all be the same type of material. Many municipalities have days when they pick up scrap metal, glass and plastics and some communities are urged to put the three types of materials in separate containers, but sometimes consumers sort the objects into the wrong category of waste. So, how is the waste accurately separated for recycling? Magnets can remove some metals from a moving conveyer belt.  Other metals and glass of various colors are sorted by hand.

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And, how can the plastics be separated? Magnets cannot be used. Visual inspection, even with the aid of recycling codes, is tedious. Can density help?

This lab starts with a demonstration, allows time for students to practice with the materials and apparatus, and ends with the students designing and running an experiment to identify unknown plastics.

This table identifies different polymers and their store-bought products.

Orlinsky_Table1

Table of different Polymers identified by densities and solution preparation

Orlinsky_Table2

Teacher Demonstration:

  • Apparatus:  seven (7) 250-mL beakers, graduated cylinders, stirring rod, long forceps.
  • Prepare the seven (7) beakers with the different density solutions according to the chart above.
  • Demonstrate how samples of plastic sink or float in the appropriate liquids.
  • Discuss reasons why the plastics float or sink.

Guided Student Practice:

  • Apparatus: 250-mL beaker, forceps
  • Materials: distilled water, access to beakers previously used in demonstration, two (2) plastic samples (with coded identity) for each group
  • Procedure: (DONE IN GROUPS OF 4)
    • Assign two (2) different types of plastic to each pair in groups of four (4).
    • Examine the plastics and record its code and its appearance.
      • Sample Code __________________ Sample Code __________________
      • Appearance ___________________ Appearance ___________________
    • Using the solutions, observe if the plastic to floats or sinks.
    • Verify that the plastic you have floats or sinks in the correct solution.

Student Independent Practice/Lab:

  • Objective:  Each group must predict and design a way to identify the plastics using only the known density solutions.
  • Instructions for students: Plan how to use the apparatus and materials you have been assigned to identify the pieces of plastic.
  • Students have access to the beakers from the previous demonstration, plus distilled water and normal laboratory equipment.
  • Each team executes the identification plan for the pieces of plastic they have been given.
  • To add a challenge:  all known solutions must be in a single container and students cannot have 7 beakers to test all solutions.

Use of models:

  • Using words, pictures or a physical model, show how a municipality could separate the large volume of waste plastics it collects.

Written by Jeff Orlinsky

Jeff Orlinsky

Jeff Orlinsky teaches science at Warren High School and is a member of CSTA.

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Accelerating into NGSS – A Statewide Rollout Series Now Accepting Registrations

Posted: Friday, January 19th, 2018

Are you feeling behind on the implementation of NGSS? Then Accelerating into NGSS – the Statewide Rollout event – is right for you!

WHO SHOULD ATTEND
If you have not experienced Phases 1-4 of the Statewide Rollout, or are feeling behind with the implementation of NGSS, the Accelerating Into NGSS Statewide Rollout will provide you with the greatest hits from Phases 1-4!

OVERVIEW
Accelerating Into NGSS Statewide Rollout is a two-day training geared toward grade K-12 academic coaches, administrators, curriculum leads, and teacher leaders. Check-in for the two-day rollout begins at 7:30 a.m., followed by a continental breakfast. Sessions run from 8:00 a.m. to 4:15 p.m. on Day One and from 8:00 a.m. to 3:30 p.m. on Day Two.

Cost of training is $250 per attendee. Fee includes all materials, continental breakfast, and lunch on both days. It is recommended that districts send teams of four to six, which include at least one administrator. Payment can be made by check or credit card. If paying by check, registration is NOT complete until payment has been received. All payments must be received prior to the Rollout location date you are attending. Paying by credit card secures your seat at time of registration. No purchase orders accepted. No participant cancellation refunds.

For questions or more information, please contact Amy Kennedy at akennedy@sjcoe.net or (209) 468-9027.

REGISTER

http://bit.ly/ACCELERATINGINTONGSS

DATES & LOCATIONS
MARCH 28-29, 2018
Host: San Mateo County Office of Education
Location: San Mateo County Office of Education, Redwood City

APRIL 10-11, 2018
Host: Orange County Office of Education
Location: Brandman University, Irvine

MAY 1-2, 2018
Host: Tulare County Office of Education
Location: Tulare County Office of Education, Visalia

MAY 3-4, 2018
Host: San Bernardino Superintendent of Schools
Location: West End Educational Service Center, Rancho Cucamonga

MAY 7-8, 2018
Host: Sacramento County Office of Education
Location: Sacramento County Office of Education Conference Center and David P. Meaney Education Center, Mather

JUNE 14-15, 2018
Host: Imperial County Office of Education
Location: Imperial Valley College, Imperial

Presented by the California Department of Education, California County Superintendents Educational Services Association/County Offices of Education, K-12 Alliance @WestEd, California Science Project, and the California Science Teachers Association.

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.

The Teaching and Learning Collaborative, Reflections from an Administrator

Posted: Friday, January 19th, 2018

by Kelly Patchen

My name is Mrs. Kelly Patchen, and I am proud to be an elementary assistant principal working in the Tracy Unified School District (TUSD) at Louis Bohn and McKinley Elementary Schools. Each of the schools I support are Title I K-5 schools with about 450 students, a diverse student population, a high percentage of English Language Learners, and students living in poverty. We’re also lucky to be part of the CA NGSS K-8 Early Implementation Initiative with the K-12 Alliance. Learn More…

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Written by NGSS Early Implementer

NGSS Early Implementer

In 2015 CSTA began to publish a series of articles written by teachers participating in the California NGSS k-8 Early Implementation Initiative. This article was written by an educator(s) participating in the initiative. CSTA thanks them for their contributions and for sharing their experience with the science teaching community.

2018 CSTA Conference Call for Proposals

Posted: Wednesday, January 17th, 2018

CSTA is pleased to announce that we are now accepting proposals for 90-minute workshops and three- and six-hour short courses for the 2018 California Science Education Conference. Workshops and short courses make up the bulk of the content and professional learning opportunities available at the conference. In recognition of their contribution, members who present a workshop or short course receive 50% off of their registration fees. Click for more information regarding proposals, or submit one today by following the links below.

Short Course Proposal

Workshop Proposal 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.

CSTA’s New Administrator Facebook Group Page

Posted: Monday, January 15th, 2018

by Holly Steele

The California Science Teachers Association’s mission is to promote high-quality science education, and one of the best practice’s we use to fulfill that mission is through the use of our Facebook group pages. CSTA hosts several closed and moderated Facebook group pages for specific grade levels, (Elementary, Middle, and High School), pages for district coaches and science education faculty, and the official CSTA Facebook page. These pages serve as an online resource for teachers and coaches to exchange teaching methods, materials, staying update on science events in California and asking questions. CSTA is happy to announce the creation of a 6th group page called, California Administrators Supporting Science. Learn More…

Written by Guest Contributor

From time to time CSTA receives contributions from guest contributors. The opinions and views expressed by these contributors are not necessarily those of CSTA. By publishing these articles CSTA does not make any endorsements or statements of support of the author or their contribution, either explicit or implicit. All links to outside sources are subject to CSTA’s Disclaimer Policy: http://www.classroomscience.org/disclaimer.

Find Your Reason to Engage

Posted: Monday, January 15th, 2018

by Jill Grace

I was recently reflecting on events in the news and remembered that several years ago, National Public Radio had a story about a man named Stéphane Hessel, a World War II French resistance fighter, Nazi concentration camp survivor, and contributor to the United Nation’s Universal Declaration of Human Rights. The story focused on a book he had published, Time for Outrage (2010).

In it, Hessel makes the argument that the worst attitude is indifference:

“Who is in charge; who are the decision makers? It’s not always easy to discern. We’re not dealing with a small elite anymore, whose actions we can clearly identify. We are dealing with a vast, interdependent world that is interconnected in unprecedented ways. But there are unbearable things all around us. You have to look for them; search carefully. Open your eyes and you will see. This is what I tell young people: If you spend a little time searching, you will find your reasons to engage. The worst attitude is indifference. ‘There’s nothing I can do; I get by’ – adopting this mindset will deprive you of one of the fundamental qualities of being human: outrage.  Our capacity for protest is indispensable, as is our freedom to engage.”

His words make me take pause when I think of the status of science in the United States. A general “mistrust” of science is increasingly pervasive, as outlined in a New Yorker article from the summer of 2016. 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.