Part C: Calculating Density

8. To calculate the density of silicon, divide its mass by its volume.

   $Density=\genfrac{}{}{0.1ex}{}{Mass}{Volume}$

   Record the density of silicon in your data table.

9. Repeat Step 8 to find the densities of tin and lead.

10. Make a line graph that shows the relationship between the densities of silicon, tin, and lead and the periods in which they are located in the periodic table. Place the number of the period (from 1 to 7) on the horizontal axis and the density (in g/cm³) on the vertical axis. Draw a straight line that comes as close as possible to all three points.

11. Germanium is in Period 4. To estimate the density of germanium, draw a dotted vertical line from the 4 on the horizontal axis to the solid line. Then, draw a dotted horizontal line from the solid line to the vertical axis. Read and record the density of germanium.

12. Wash your hands with warm water and soap before you leave the laboratory.

Analyze and Conclude

1. Classifying List lead, silicon, and tin in order of increasing density.

2. Comparing and Contrasting How does your estimate of the density of germanium compare with the actual density of germanium, which is 5.3 g/cm³?

3. Calculating Use the formula for percent error (PE) to calculate a percent error for your estimate of the density of germanium.

   $PE=\genfrac{}{}{0.1ex}{}{Estimatedvalue-Acceptedvalue}{Acceptedvalue}\times 100$

4. Drawing Conclusions How does the density of the elements change from silicon to lead in Group 4A?

Go Further Use reference books or sites on the Internet to research properties of Group 4A elements. Construct a graph that shows how another property, such as melting point or boiling point, varies among the Group 4A elements you explored. Determine whether knowing the values for three of the elements would allow you to accurately predict a value for the fourth element.

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