Melting and Freezing

AAAS Science NetLinks
Type Category
Instructional Materials
Experiment/Lab Activity , Instructor Guide/Manual , Activity , Demonstration
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be "fully aligned," the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.



This lesson is designed for K-2 students. In the lesson, students will gain an understanding of the water cycle and make observations of water in several different forms (solid, liquid, gas) to gain critical understanding that water is constantly changing states. This lesson is the 3rd in a three part series of lessons that helps students apply this understanding to other forms of matter, specifically with melting and freezing.

Intended Audience

Educator and learner
Educational Level
  • Grade 2
  • Grade 1
  • Kindergarten
  • Early Elementary
  • Elementary School
  • Pre-Kindergarten
Access Restrictions

Free access - The right to view and/or download material without financial, registration, or excessive advertising barriers.

Performance Expectations

2-PS1-4 Construct an argument with evidence that some changes caused by heating or cooling can be reversed and some cannot.

Clarification Statement: Examples of reversible changes could include materials such as water and butter at different temperatures. Examples of irreversible changes could include cooking an egg, freezing a plant leaf, and heating paper.

Assessment Boundary: none

This resource is explicitly designed to build towards this performance expectation.

Comments about Including the Performance Expectation
The activities included in the lesson involve melting ice, chocolate chips, and margarine by holding plastic bags filled with the individual items in students hands. In order to connect to local weather, students could place bags of the items in the sun. They could then compare results between bags held by students and bags placed in the sun. To address the Performance Expectation, students would have to construct a verbal or written argument using their evidence. This could be done debate style, in small groups in front of the class, or individually written.

Science and Engineering Practices

This resource appears to be designed to build towards this science and engineering practice, though the resource developer has not explicitly stated so.

Comments about Including the Science and Engineering Practice
It is suggested that the teacher ensure there is time built in the lesson for students to construct an argument using the evidence they found during their experiments.This could be done in small groups or individually, but is essential to ensure the Practice is addressed.

This resource is explicitly designed to build towards this science and engineering practice.

Comments about Including the Science and Engineering Practice
To meet the Practice, students could should work collaboratively in small groups.

Disciplinary Core Ideas

This resource is explicitly designed to build towards this disciplinary core idea.

Comments about Including the Disciplinary Core Idea
To ensure that the Core Idea is fully addressed, it is suggested that this lesson is completed following the other two lessons noted in the link. This will allow for students to make connections to prior knowledge about water in different forms and apply their prior knowledge to the margarine, chocolate chips, and ice.

Crosscutting Concepts

This resource is explicitly designed to build towards this crosscutting concept.

Comments about Including the Crosscutting Concept
In order to meet the Crosscutting Concept, the melting activity should be completed several times in order to establish a pattern. To establish an observable pattern more than one set of materials could be used. One set could be the control and the other could have one variable changed to see if a pattern could be established.

Resource Quality

  • Alignment to the Dimensions of the NGSS: This activity involves class discussion and hands-on activities for students. It provides opportunities for students to make sense of phenomena. The lesson allows for three-dimensional learning.

  • Instructional Supports: This lesson links to other lessons in the series to provide better understanding of the concepts being taught.

  • Monitoring Student Progress: Class discussion questions are included with the lesson. It does not include written assessment.

  • Quality of Technological Interactivity: There is no technological component to this lesson.