CHANGING MATTER AND MASS

1
LESSON 8

• CHANGING MATTER AND MASS

2
INTRODUCTION STUDENT GUIDE P. 74
3
OBJECTIVES

• DISCUSS WHAT HAPPENS TO THE MASS OF SUBSTANCES
  WHEN THEY CHANGE STATE.
• CONDUCT AN EXPERIMENT TO INVESTIGATE WHETHER ANY
  CHANGES OF MASS OCCUR WHEN ICE MELTS.

4

• DISCUSS SOURCES OF EXPERIMENTAL ERROR WITHIN YOUR
  EXPERIMENT.
• DESIGN AN INQUIRY TO TEST YOUR OWN PREDICTION
  ABOUT ANY CHANGES OF MASS THAT MAY OCCUR WHEN
  WATER FREEZES.

5
GETTING STARTED

• WRITE IN YOUR SCIENCE NOTEBOOK YOUR PREDICTION OF
  WHAT WILL HAPPEN TO THE MATTER IN THE FOLLOWING
  SITUATIONS?

6

• THE MASS OF AN ICE CUBE WHEN IT MELTS
• THE MASS OF THE WATER IN AN ICE CUBE TRAY WHEN IT
  FREEZES
• THE MASS OF THE WATER IN A TEA KETTLE WHEN IT
  BOILS

7
COLLECT TOTE TRAY OF MATERIALS

• 1 SMALL PLASTIC SODA BOTTLE WITH SCREW CAP
• 1 250-ML BEAKER
• 1 PAPER TOWEL
• ICE
• BALANCE

8
INQUIRY 8.1 MASS AND MELTING

• USING THE MATERIALS, DEVISE AN INQUIRY TO TEST
  YOUR PREDICTION ABOUT WHAT HAPPENS TO THE MASS OF
  ICE WHEN IT MELTS.
• CONSIDER
• METHOD
• MEASUREMENTS
• PRECAUTIONS TO AVOID ANY LOSS OF MASS
• RECORD PROCEDURE ON STUDENT SHEET 8.1

9

• WHAT IDEAS DID YOUR GROUP COME UP WITH?
• PUT THE EQUIVALENT OF ABOUT ONE CUBE OF CRUSHED
  ICE IN THE SODA BOTTLE.
• SCREW ON THE LID
• MEASURE THE MASS OF THE BOTTLE AND ICE
• WAIT FOR THE ICE TO MELT
• USE A PAPER TOWEL TO WIPE ANY CONDENSATION ON
  OUTSIDE OF BOTTLE
• REWEIGH THE APPARATUS.

10

• Draw this table in your notebook to record your
  results.

• Well move on to inquiry 8.2 while we wait for
  the ice to melt.

11
INQUIRY 8.2 INVESTIGATING MASS AND FREEZING

• WHAT PROCEDURE WOULD YOU USE TO TEST YOUR
  PREDICTION ABOUT THE MASS OF WATER WHEN IT
  FREEZES?
• USE 3 MINUTES TO DISCUSS IN YOUR GROUPS.
• SHARE.

12

• RECORD THE FOLLOWING IN YOUR NOTEBOOK
• A. PUT WATER IN A PLASTIC BOTTLE.
• SEAL THE BOTTLE
• MAKE SURE THE BOTTLE IS DRY.
• MEASURE THE MASS OF THE BOTTLE AND THE WATER.
• PLACE THE BOTTLE IN A FREEZER UNTIL THE WATER
  FREEZES.
• DRY THE BOTTLE.
• QUICKLY MEASURE THE MASS OF THE BOTTLE ICE
  BEFORE CONDENSATION CAN FORM.

13

• SET UP THE EXPERIMENT.
• LABEL YOUR BOTTLES.
• PUT BOTTLES IN FREEZER.

• RETURN TO INQUIRY 8.1 TO SEE
• IF THE ICE HAS MELTED.
• MEASURE THE MASS OF THE
• MELTED ICE AND BOTTLE.
• DONT FORGET TO WIPE ANY
• CONDENSATION OFF THE
• OUTSIDE OF THE BEAKER BEFORE
• MEASURING.

14
RECORD YOUR RESULTS ON THE CLASS DATA TABLE.

• ANSWER THE FOLLOWING QUESTIONS IN STEPS 4A AND 4B
  ON STUDENT SHEET 8.1

15

• WHAT HAPPENED TO THE MASS OF THE ICE WHEN IT
  MELTED?
• WHY DID YOU USE A SEALED CONTAINER FOR THIS
  EXPERIMENT?

16
REFLECTIONS 8.1 RECORD ON YOUR STUDENT SHEET 8.1

• 6. DID EVERYONE OBTAIN THE SAME RESULTS? WHY OR
  WHY NOT?
• 7a. WHICH MEASUREMENTS ARE VERY DIFFERENT FROM
  THE OTHERS?
• 7b. ELIMINATE THE VERY DIFFERENT MEASUREMENTS
  AND CALCULATE THE AVERAGE CHANGE IN MASS OF THE
  REMAINING MEASUREMENTS.

17

• 7c. WHAT WAS THE MOST FREQUENT MEASUREMENT GIVEN
  FOR CHANGE OF MASS?
• 7d. WHAT DO YOU CONCLUDE FROM THESE RESULTS?

18
REFLECTIONS 8.2

• RECORD THE MASS OF THE BOTTLE AND WATER AFTER IT
  WAS FROZEN?
• RECORD YOUR GROUPS RESULTS ON THE CLASS DATA
  TABLE.
• CALCULATE THE AVERAGE.
• ANSWER 3 ON YOUR STUDENT SHEET 8.2. WHAT
  HAPPENS TO THE MASS OF WATER WHEN IT FREEZES?