Chemical vs. Physical Changes
Name __________________________
Date _________________ Period ____
Directions Part A: Read each scenario below and answer the questions that follow.
Scenario 1: You have an unknown liquid in a beaker. You add a powder to the liquid. The solution
begins to bubble and smoke rises.
a. Is this an example of a physical or chemical change? Explain.
b. Is it possible to retrieve the powder? Explain.
Scenario 2: You go to a pet store and decide to buy a baby nurse shark. Nurse sharks are ocean
dwelling creatures, so you set up a fish tank that resembles the animal’s natural environment.
a. To replicate the water a shark lives in, you mix salt (NaCl) into the water. Is this a chemical
or physical change? Explain.
b. You feed your shark goldfish while he is little. Goldfish enter the shark as goldfish, but after
passing through the shark’s digestive system, are reduced to waste. Is this an example of a
physical or chemical change? Explain.
c. After your tank has been set up you notice that the water level has dropped. Is this an
example of a physical or chemical change? Explain.
Scenario 3: Due to the cold weather and the fall harvest of pumpkins, your mom decides to bake you a
pumpkin pie.
a. The dough for the crust of the pie consists of butter, flour, water and a few other ingredients.
After the dough is put in the oven, it becomes hard and turns golden brown. Is this an example
of a physical or chemical change? Explain.
b. Before the filling can be made the pumpkin needs to be cut in half so that the seeds can be
removed. Is this an example of a physical or chemical change? Explain.
Scenario 4: While on a trip to the Fort Worth Zoo, you decide to watch the polar bears at feeding time.
To remember your trip to the zoo, you buy a wax polar bear from the machine for a dollar.
a. For the machine to make your figure, it heats up a ball of wax, turning it into a liquid
substance. Is this transformation an example of a physical or chemical change? Explain.
b. This liquid wax is then poured into a mold. It cools to take the shape of a polar bear. Is this
transformation an example of a physical or chemical change? Explain.
Scenario 5: One weekend you and friend are bored so you head to a nearby field to play catch. The
field is wet from the night before and your shoes have poor traction.
a. Your buddy throws the ball too high and too far to the right. You run after the football and
dive. Your wrist plants into the mud and you snap your two forearm bones (the ulna and
radius). Is breaking your bones an example of a physical or chemical change? Explain.
Scenario 6: Homecoming is right around the corner and you want to look good.
a. You go to the barber shop to get a haircut. What type of change is occurring as the barber
snips your hair? Explain.
b. The barber’s scissors are awfully dull. You notice there is rust on the edges of them. What
kind of change explains this? Explain.
Scenario 7: On a camping trip, night falls and it is time for dinner. Since rubbing two sticks together
takes too long, you take the easy out and make a fire with paper and kindling wood.
a. Chopping the large pieces of wood into kindling is what type of change? Explain.
b. Crumpling the paper into little bunches to place at the bottom of the fire pit demonstrates
what type of change? Explain.
c. The burning of the wood and paper illustrates what type of change? Explain.