Properties of Matter: Investigation 1 –
Italicized font represents information to be shared orally or physically completed with the students at this time.
The non-italicized font represents additional information included to support the teacher’s understanding of the content being introduced within the CELL.
Remind students that by observing a sample of matter and measuring its chemical and physical properties, we gradually acquire enough information to characterize it and distinguish it from other kinds of matter. This is the first step in the development of chemical science, in which interest is focused on specific types of matter.
Remind students that chemists use the principles and theories of chemistry and mathematics to help invent and improve products and processes. A chemist might evaluate a new food additive to find out if it improves the texture of a breakfast cereal or test ingredients in order to help develop a new tear-less baby shampoo.
Inform students that the Investigation is designed to help them to answer the following Focus Questions:
- Can you tell the difference between an element and a compound by measuring mass and volume? Student answers will vary. It is likely that students will not be able to discern the difference between substances that are elements and those that are compounds.
- Can you determine the identity of an unknown substance by observing its mass and volume? Students will likely indicate that without previous knowledge of the properties of all elements and compounds or samples of known elements or compounds at their disposal, a definite identification using just mass and volume is not possible.
Note: These questions are located in students’ SDRs at the beginning and end of the Investigation.
Note: These are succinct responses to the Focus Questions and are placed here for your reference at this time. Fully developed responses to the Focus Questions can be found on the PostLab page.
As a class, read the Background(s) in the Investigation. Have students read the information aloud or silently to themselves. When students have finished, discuss the following concepts as a class:
- Matter can be described as anything that takes up space and has mass.
- An element is a type of matter that cannot be broken down into another substance by chemical reactions.
- A compound is a type of matter that is made up of two or more elements.
- A physical property is a characteristic that can be measured or observed without changing the identity of the substance.
- A graduated cylinder is used to measure the volume of liquids.
- A mathematical formula is used to measure the volume of a cube.
- The volume displacement method is used to measure the volume of irregularly shaped objects.
Note: These concepts are integrated into the Background(s) and are used to deepen students’ comprehension of the big ideas.
LEARN THE LabLearner LINGO
The following list includes Key Terms that are introduced in the Investigation Background(s). They should be used, as appropriate, by teachers and students during everyday classroom discourse.
- physical property
Note: Definitions to these terms can be found on the Introduction page to the CELL.
Note: Additional words may be bolded within the Background(s). These words are not Key Terms and are strictly emphasized for exposure at this time.
SET FOR SUCCESS
- Discuss the difference between elements and compounds including the concept that compounds result from chemical combinations of different elements.
- Explain that within the CELL, students will first investigate physical properties of elements and compounds.
- Explain to students that, during the Investigation, they will find the mass and volume for six unknown samples.
- Explain to students that some of the unknown samples are elements and some are compounds.
- Complete the Recall section in students’ SDRs.
- Play the video below. Stop to ask students questions or answer students’ questions when necessary. Remind students to follow along with their SDRs and make any notes that they think might be helpful.
- After the video, direct students to divide into their lab groups to discuss their strategy for the lab. For example, they may assign certain group members to perform specific functions during the lab.
Note: The purpose of the video is to allow students to anticipate the laboratory experience they will soon encounter. Students should leave this PreLab session with a firm idea of what to expect and how to perform in the lab.
Note: Homework is posted below the video.
Tell students that they should review the Investigation in preparation for the Lab.