Look for: Water is made of particles of matter

4.C Develop a model to describe why mass is lost in some conditions but not others (open systems versus less-open systems), using a particle model of matter for liquids and gases.

Students’ responses to the first question on the handout Explanations and Predictions of Lids and Covers are a good opportunity to assess the use of these ideas after they have been (re)established/agreed upon by the class at the end of day 3. In the responses look for these ideas:

• Water is made of particles of matter.
• Particles of water go into the air over time (evaporation), leaving fewer particles of water behind in the liquid.
• Particles of water in the air can’t go through a solid lid.
• Particles of water in the air may be able to go through gaps in the solid parts of the system (e.g., the straw hole or where the lid meets the walls of the cup).

This is also an opportunity to determine if students have a particulate model of matter for solids from 5th grade. This model will be (re)established in Lesson 6. But you can pre-assess student understanding of it now, by looking for this idea in their responses to questions 1 and/or 4 on Explanations and Predictions of Lids and Covers:

The cup’s solid walls and lid are also made of particles. These particles are so closely spaced together that gas particles can’t fit between them to get into or out of the system.

Check to see if students apply particulate models of matter to explain this process. In NGSS, in 5th grade students should have developed a particulate model of matter for liquids and gases and used it to explain phenomena such as the gradual disappearance of liquid water in an open system (evaporation).

Additional Lesson 4 Teacher Guidance

SUPPORTING STUDENTS IN MAKING CONNECTIONS IN ELA

CCSS.ELA-Literacy.RST.6-8.3: Follow precisely a multistep procedure when carrying out experiments, taking measurements, or performing technical tasks.

Students follow a multistep procedure in days 1 and 2 of this lesson. Asking students to keep a record of each step they complete by putting a checkmark near that step can help them develop a transferable approach to tracking their progress on other technical tasks that are in multistep procedure form in other contexts.

SUPPORTING STUDENTS IN MAKING CONNECTIONS IN MATH

CCSS.MATH.Content.6.NS.C.5: Understand that positive and negative numbers are used together to describe quantities having opposite directions or values (e.g., temperature above/below zero, elevation above/below sea level, debits/credits, positive/negative electric charge); use positive and negative numbers to represent quantities in real-world contexts, explaining the meaning of 0 in each situation.

• CCSS.MATH.Content.6.SP.A.3: Recognize that a measure of center for a numerical data set summarizes all of its values with a single number, while a measure of variation describes how its values vary with a single number.
• In this lesson’s three investigations, students measure, calculate, and represent drops in temperature and mass in the cup systems as negative numbers, increases in temperature and mass as positive numbers, and no change as 0 in each situation. Students pool their data to calculate class mean.