8th Grade Science Guide

8.1: Chemistry 3 Dimensions & Progressions

Unit 2

● I can make observations and inferences while watching a phenomena.

● Students watch a reaction that occurs in a closed system. ● Alternative Phenomena - burning wood vs. burning steel wool. Measure mass before and after.

● Teacher Instructions

Activity: Conservation of Matter in a Physical Change

Objective

Overview

Materials

● I can develop a model describing atoms and molecules ability to

● Students collect ice, put it in their container, weigh it. Wait for it to melt and

● snow/ice, a container that can be sealed, a scale/balance, paper towels. ● student sheet

combine and recombine. (conservation of matter)

re-weigh it. Students have a lab write up to record the data.

Activity: Conservation of Matter in a Chemical Change

Objective

Overview

Materials

● I can develop a model describing atoms and molecules ability to

● Students perform a

● Calcium chloride, sodium bicarbonate, phenol red or Bromothymol blue, ziplock bags, balance (or scale) ● Ziploc Bag Lab

reaction in a bag to revisit signs of a chemical change and to test the law of conservation of mass.

combine and recombine. (conservation of matter)

Activity: Recognizing Conservation of Mass

Objective

Overview

Materials

● I can develop a model describing atoms and molecules ability to

● Teacher performs demos or students measure and experience conservation of mass. Link to background knowledge (from previous parts of the unit): How do you recognize a chemical change and how do you recognize a physical change?

● This video has a few examples of how

students can observe the law of conservation of mass. But it is recommended that the teacher should get the supplies and allow the students to measure and experience it for themselves.

combine and recombine. (conservation of matter)