Lesson 2: Freezing and Melting

2nd Grade Matter Unit Blueprint—Lesson 2: Freezing and Melting

Pacing Suggestions:

Day 1- Procedure Steps 1-3 on page 37 in TG
Day 2-Procedure Steps 6-9, Final Activities Steps 1-4 on pages 37-40 in TG

Teacher Resources:
Tips	The Melting Race Adobe® Reader® (PDF) The Melting Race (Microsoft Word Format)

Essential & Unit Questions ¹

Benchmarks ²

Formative and Summative Assessments ³

Using Assessments to Monitor Student Learning

How are ice and water (liquid) alike and different?

How can water be changed back and forth between a solid and a liquid?

How does the amount of water change if it is frozen and then melted?

11C(K-2)#1: Things change in some ways and stay the same in some ways.

4B(K-2)#2: Water can be a liquid or a solid and can be made to go back and forth from one form to the other. If water is turned into ice and then the ice is allowed to melt, the amount of water is the same as it was before freezing.

Observe ice cube trays and discuss changes (See Procedure Steps 1 & 2 on page 37 in Teacher’s Guide.)

Experimental design of “The Melting Race” (use teacher-generated sheet available under “Teacher Resources—Items to Print”) and class discussion of experiment (See Procedure Steps 3, 6-9 on pages 37 & 38 in Teacher’s Guide and Final Activities Step 2 on page 38 in Teacher’s Guide.)

Click to view a sample of student work. (Acrobat PDF)

Criteria to consider while students observe ice cube trays and discuss the change observed:

Did the students’ predictions match their observations?
Can students generalize from the experiment water changes into ice when subjected to cold temperatures?
Do student know that the ice and water are still the same substance?
Do students recognize some differences between the ice and water (ex: the ice cube is hard and retains its own shape)?

Criteria to consider while observing students create their strategy/procedure for melting the ice cube:

Do students know that the ice cube will melt if it is left out?
Do students create a plan that is related to heat (rubbing, placing by a heat source…), thus indicating they understand how to make the ice cube melt faster than just sitting out?

12B(K-2)#1: Use whole numbers and simple, everyday fractions in ordering, counting, identifying, measuring, and describing things and experiences.

“The Melting Race” data (timed)

Criteria to consider when reviewing students’ lab data:

Are students able to calculate the amount of time it took to melt the ice cube?

What are some ways to describe objects?

4D(K-2)#1: Objects can be described in terms of the materials they are made of (clay, cloth, paper, etc.) and their physical properties (color, size, shape, weight, texture, flexibility, etc.).

Properties chart and class discussion (See Final Activities Step 1 on page 38 in Teacher’s Guide.)

Criteria to consider during class generation of the Properties chart:

Are students using physical properties to describe how the ice cube changed?

What happens to water left out in an open container?

What happens to water left in a container with a lid?

4B(K-2)#3: Water left in an open container disappears, but water in a closed container does not disappear.

Student predictions and observations of the water in their Petri dishes (See Final Activities Step 3 on pages 38 & 39, especially bullet #6 on page 39, in Teacher’s Guide.)

Criteria to consider when students make predictions:

Do students think there will be a difference between the covered and uncovered Petri dishes?
Do students know that water will “disappear” if left in an open container?
If students use the word “evaporate,” what do the students mean? (Evaporate means to turn into a gas—most students use the word incorrectly to mean that the water goes away or disappears.)

For conceptual benchmarks.
Bolded Sections indicate portion of benchmark addressed.
Unless noted as a Summative Assessment, the assessments are formative and should be used to guide teaching and learning.