Physical Properties of Matter: Tootsie Roll Properties

Matter is anything that has mass and occupies space. Different types of matter are characterized by unique chemical and physical properties. We can observe the physical properties of a substance without knowing anything about its composition. One physical property of water is that it has a density of 1 g/ml. Density is a property of matter equal to its mass per unit volume. An object with a density less than 1 g/ml will float on water, but an object with a density greater than 1 g/ml will sink. In this activity you will calculate the density of a Tootsie Roll to see whether it will sink or float in water.

Materials

Snack-size Tootsie Roll; Cup of water; Ruler

Activity

1. To calculate the density of a Tootsie Roll, use the formula D = m/v, where D represents density, m is mass, and v is volume.
   1. Find the volume of a Tootsie Roll. Since the candy is cylindrical in shape, use the formula V = 3.14 × r²h. Unwrap the Tootsie Roll and measure its height (h) and radius (r) in centimeters. Use this information and the formula to find the volume of the Tootsie Roll.
   2. Most Tootsie Rolls this size have a mass of about 7 grams. Use the density formula to calculate the density of the Tootsie Roll. Remember that 1 cm3 is equal to 1 ml.
2. Judging by your calculations, do you expect the Tootsie Roll to sink or float in water?
3. Place the Tootsie Roll in the cup of water to see whether your calculations were correct.

Follow-Up Questions

1. According to your calculations, what was the density of the Tootsie Roll?
2. Did you expect it to sink or float in water? Were you right?

Answers

1. Answers will vary, but the density of the Tootsie Roll should be less than 1 g/ml.
2. Answers will vary.

Extension

Density is one physical property of a Tootsie Roll. Look at the Tootsie Roll and list three other physical properties it has. List three physical properties of water. How do they compare?