Name:

# Density Measurement Activity

## Background:

Density is an intrinsic property of an object. Density is the measure of the mass per unit volume of an object. **Density = mass / volume**. The metric units for density are g / cm^{3} or kg / m^{3}.

## Materials List:

- block of wood
- sinker
- marble
- 10 pennies

## Tools List:

- triple-beam balance
- metric ruler
- graduated cylinder
- overflow can

## Procedure (part 1 - your estimates):

- Get the materials and return to your desk.
- In data table 1, record the measurements you will need to make, the tool you will use and your estimates of the measurements. Calculate the density of the objects using your estimates.

Have the instructor sign off your estimates.

## Data Table 1 - your estimates (with units)

Object | Measurement To Make | Tool to Use When Measuring | Your Estimate | Estimated Density |
---|---|---|---|---|

Block of wood | mass |
|||

volume |
||||

Sinker | ||||

Penny | ||||

10 pennies | ||||

Marble | ||||

### Have the instructor sign off your estimates. ____________________________

## Procedure (part 2 - your measurements):

- Get the materials and tools then return to your desk.
- Make the measurements and record in data table 2.
- Calculate the actual densities and answer the analysis questions.

## Data Table 2 - your measurements and density calculations (with units)

Object | Actual Mass | Actual Volume | Density |
---|---|---|---|

Block of wood | |||

Sinker | |||

Penny | |||

10 pennies | |||

Marble |

## Analysis:

On a separate sheet of paper, use complete sentences to answer these questions.

- Is the kilometer, meter, centimeter or millimeter most appropriate for expressing the length and width of the block? Why?
- For which object was your estimates the most accurate? Why?
- For which object was your estimates the least accurate? Why?
- Explain in words the entire process you used to find the density of the marble?
- Contrast the density for a penny you obtained for the single and the 10 pennies?
- Why would there be differences in the penny density measurement?
- A small chain known to be made of gold has a mass of 328.1 grams. When the chain is placed in a graduated cylinder of water, the water level rises from 8 ml to 25 ml. What is the density of gold? Show your calculations.
- Another golden chain has a mass of 315 grams. The graduated cylinder water level changes from 5 ml to 26 ml. What is the density of the chain? Show your calculations.
- Why might the second chain have a different density?
- Explain how knowing the density of a material would allow you to predict if it floats in water.