PHYSICAL AND CHEMICAL CHANGES

 An Online Treasure Hunt
for First Year High School (Science)

Introduction

Look around you. Do things seem the same as they were when you were very young? Examine yourself. Are you the same as when you were a small child?

It might seem like things haven’t changed. But all matter changes, sometimes in ways that are not obvious to us. The two general types are physical and chemical change.

Let’s study physical and chemical changes through this online treasure hunt. The rules of the game are simple. Working in groups of three or four, find the answers to the following questions on physical and chemical change. The answers are to be found in the websites listed below. Click on the URL or address to be able to open a website. Read each website carefully. Write your answers to the questions neatly on a clean sheet of paper with the names of group members written on it.

Afterwards, answer the Big Question. Be sure to work together and complete the activity in one hour. When you’re done, you should have an overview of physical and chemical change in matter.  

Questions

1. Both chemical and physical change can result in a change in phase, color, and temperature in the substances involved. What are the ultimate indicators of chemical change—meaning, these happen only when the change is chemical and not when the change is physical?

2. What happens to chemical bonds when there is a physical change in a substance?

3. Do chemical change and physical change always occur separately? That is, when there is a chemical change, does that mean there is NO physical change? If there is a physical change, does that mean there is NO chemical change? Explain your answer.

4. What kind of change is soil erosion?

5. What is the role of energy in physical and chemical change?

6. Give your own examples of an endothermic reaction and an exothermic reaction. 

 
Resources

Distinction between physical and chemical change
http://dl.clackamas.cc.or.us/ch104-01/DistChemPhyChange.htm

The difference between physical and chemical change
http://www.physlink.com/Education/AskExperts/ae244.cfm

To react or not to react?
http://www.usoe.k12.ut.us/curr/science/sciber00/8th/matter/sciber/chemtype.htm

What is physical change
http://www.edinformatics.com/math_science/p_change.htm

Physical and chemical changes
http://www.clickandlearn.org/Gr9_Sci/Physica_chemical_changes.htm

Lizards: chemical vs. physical change
http://www.newton.dep.anl.gov/askasci/chem03/chem03194.htm

 
The Big Question

Look around the classroom and school and identify eight changes in matter that are taking place. Be sure that you are naming the process of change and not its product. For example, say “rotting of vegetables”, not “rotten vegetables”. Identify whether each change is physical or chemical and whether it is endothermic or exothermic. Be sure both types are represented.

You might want to present your answers in the form of a table like the one below where you write the specific changes in column 1 and then tick or place a check mark under column 2 if the change is physical or under column 3 if the change is chemical. Indicate whether the change is endothermic or exothermic also with a check mark in the right column.

This is still group work. Make sure everyone in your group contributes at least two changes in matter. Write you answer to the Big Question on the same sheet of paper where you wrote your answers to the small questions and submit the paper at the end of the period.

Authored by M. Sun and P. Arinto