8th Grade Science Guide

8.1: Chemistry 3 Dimensions & Progressions

Unit 2

● Pliers ● Duct tape

temperature, density, and state of matter.

Activity: Changing State - Melting

Objective

Overview

Materials

● I can relate the amount of energy added or taken away from a substance to the motion of molecules in the substance by developing a model to illustrate the relationships in particle motion relationships between temperature, density, and state of matter.

● Students will see a small piece of ice melt on an aluminum surface. Students will explain the energy transfer and molecular motion which cause the change in state from a solid to a liquid. Students will see and discuss an animation of ice melting and compare the state changes of water to the state changes of other substances. They will also investigate sublimation of dry ice through a teacher demonstration, or video if dry ice is not readily available.

● Lesson Plan Materials for Each Group

● 2 small pieces of ice ● 2 small clear plastic cups ● Water Materials for the Demonstration ● Ice ● Dry Ice ● Brown paper towel ● Coldwater ● Hot water DO NOT ALLOW STUDENTS TO HANDLE DRY ICE.

Activity: Moving Molecules in a Solid

Objective

Overview

Materials

● I can relate the amount of energy added or taken away from a substance to the motion of molecules in the substance by developing a model to illustrate the relationships in particle motion relationships between temperature, density, and state of matter.

● Students will see a

● Lesson Plan ● Ball and ring designed specifcally for this demonstration ● Bunsen burner for heating the ball ● Room-temperature water (to cool the ball)

demonstration with a metal ball and ring showing that heat causes atoms to spread a little further apart. They will also see that cooling a solid causes the atoms to get a little closer together. The same rules they discovered about liquids also apply to solids.