Return to Chemistry Index
Bonnie J. Hickerson Horace Mann
8050 S. Chappel
Chicago IL 60617
1. To investigate some characteristics of chemical changes.
2. To learn that a chemical change changes the composition of the substance.
3. To learn that the formation of gas bubbles is an indication of a chemical
4. To learn that a color change is an indication of a chemical change.
5. To learn that the disappearance of color is an indication of a chemical
For each class:
1. Apple 8. Toothpicks
2. Clear plastic cup 9. Knife
3. Vinegar 10. Popcorn popper
4. Baking soda 11. Grapes
5. Clorox bleach 12. Water
6. Food color 13. Paper
7. Household hydrogen peroxide 14. Popcorn
1. Put 1/4 cup of vinegar in a clear plastic cup. Add a teaspoon of baking soda
to the vinegar and observe.
2. Cut an apple in half and observe the exposed section's color immediately.
Observe again after a few minutes. Observe what happens to the inside
3. Put one drop of food color into a clear plastic cup and add 1/4 cup of water.
Mix with a toothpick and observe the color. Put some Clorox bleach in
another cup and add some bleach to the food color using a medicine dropper.
Keep mixing with the toothpick and observe what happens to the color.
4. Put a quarter cup of household hydrogen peroxide in a clear plastic cup
and add a slice of apple. Observe the slice of apple and check for the
formation of bubbles.
5. Place popcorn in a popper. Examine some of the extra kernels. Observe the
kernels exploding as the water inside turns to steam.
6. Put a few grapes in a container, add sugar and yeast. Stir, let stand
for a few days and observe.
Your family will vacation in Dakar, Senegal. As a student of science you
will be given the opportunity to work at a junior chemistry laboratory. You must
pass a test before you are hired at the Senegalese laboratory. Your challenge
is to classify a list of chemical and physical changes, and be able to give your
reason for each choice. You may use charts and diagrams.
List the Chemical and Physical Changes:
1. Burning of a building
2. Adding sugar to lemonade
3. Water changing to steam
4. Rusting of iron
5. Fluffy egg whites
6. Leaves changing color
7. Milk turning sour
8. Faded cloth
9. Churning of milk
10. Baking rolls
11. Ripening of tomatoes
12. A stick broken into small pieces
13. Growing vegetables
14. Formation of a gas bubble
15. Disappearance of color
16. Making ice cream
17. Using hot water to expand a metal cup
18. Opened canned fruit left out of the refrigerator for a few days
19. Digestion of food
20. Popcorn popping
21. Freezing water
Guidelines for Scoring:
Students who classify 18-21 changes correctly will be eligible to acquire the
job, and will receive a grade of A. 17-14 = B, 13-10 = C, 9-7 = D, 6 and below
is an F.