Properties of Matter: Investigation 3 –
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 soil scientists might study the composition of soils on Mars to determine what elements they contain or chemically evaluate soil nutrient levels in a farming community to determine what crops would grow best there.
Inform students that the Investigation is designed to help them to answer the following Focus Questions:
- Do compounds composed of the same elements have identical properties? Not necessarily.
- Can compounds composed of different elements have similar properties? Yes.
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:
- Compounds are substances made up of two or more elements.
- Each element in a compound is represented by a one or two letter symbol.
- Solubility refers to the ability of a solid to dissolve in a liquid.
- Miscibility refers to the ability of a liquid to mix with another liquid.
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.
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
- Explain to students that their investigation of properties of matter will continue, but will focus on additional properties of compounds.
- Review the relationship between molecular formulas and compounds emphasizing that formulas indicate the elemental composition of compounds.
- Tell students they will be investigating a new property of compounds: the solubility of liquids and solids in water.
- If necessary, review the term solubility with students.
Note: In this investigation, students will test whether solids dissolve or are soluble in water and whether liquids mix or are miscible in water.
- 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.