Chemical Tests
Lesson 16
Using the Known Solids to Identify Unknown Liquids
Students use the properties of their 5 original chemicals to identify one of the test liquids.
3. Lesson set up and Management
GLE 2.1.1 Understand how to ask questions about objects, organisms and events in the environment.
(3) Recognize the question being answered in an investigation.
GLE 2.1.2 Understand how to plan and conduct simple investigations following all safety rules.
GLE 2.1.3 Understand how to construct a reasonable explanation using evidence.
GLE 2.1.5 Understand how to report investigations and explanations of objects, events, systems and processes.
GLE 2.2.1 Understand that all scientific observations should be reported accurately and honestly even when the observations contradict expectations.
GLE 2.2.3 Understand why similar investigations may not produce similar results
GLE 2.2.4 Understand how to make the results of scientific investigations reliable.
- Students apply their testing, observing, recording and analyzing skills to a new situation, identifying the unknown liquids using the properties of the five solids they have explored in previous lessons.
3. Lesson set up and Management
Materials:
- Have a parent helper prepare the dropper bottles of the three unknown liquids ahead of time.
- Use the "Check Your Science Pail" poster board for quick student reference. Add "hand lens" and "black paper."
- Signs with each material and the amount needed to be picked up at the materials center are helpful.
Student Management:
- Review safety rules carefully with students.
- Assign one partner to be the materials manager and have that student pick up the materials from the materials center after you model how to do it.
- PREPARATION #6
- You can choose to reveal the identities of the unknown liquids after student testing or you can complete extension activity one or two.
- PROCEDURE #3
- Have a transparency of Record Sheet 16-A ready to show students and review how to use it correctly.
- ASSESSMENT
- There are so many assessment ideas you are asked to focus on. Narrow your focus down to two or three specific concepts. Have student write in their science notebooks for assessment.
Writing Support:
- Students record their test results on Record Sheet 16-A. They record their thoughts about the following questions in their science notebooks:
- Which tests gave you the most information?
- Which properties helped you identify the unknown liquid?
- Why do you think those properties were helpful?
- How did you use negative results to support your conclusions?
- As part of the post unit assessment students should go back and revisit what they wrote about the "unlabeled container scenario" and write about it again incorporating new learning.