Name ______Hour ______

Periodic Law-Density

Purpose: Predict the density of (Ge) and (Fl) based on the other group 14 elements.

Information: 1. What is the % error equation? 2. What is the density equation? 3. Write the noble e- configuration for the following elements: Si, Sn, Pb 4. What is the period # of the following elements? Si, Sn, Pb

(Don’t need to copy into lab notebook!) Mendeleev predicted the existence of Ge in 1862 with a density of 5.5 g/mL. It was discovered in 1882. Procedure: 1. a sample of , , and . 2. Determine the of each using displacement. 3. Calculate the density of each.

Data: Make sure you measure volume to 1 decimal place! Substance Period # Mass (g) Volume Volume Volume of Density before after (mL) substance (g/mL) (mL) (mL) Si Sn Pb

Analysis: 1. Make a graph of your data (1/2 page please) with the density on the vertical axis and period # on the horizontal axis. 2. Create a straight line that connects the 3 points and extend it through period 7. 3. LABEL each axis. 4. Estimate the density of germanium and label it on your graph.

Questions: 1. What happened to the density of the elements as you moved down the group? 2. Does this agree with the periodic law? Explain. (See notes) 3. Is density a physical or chemical property of ? Explain. 4. Calculate a % error for your experiment based on the actual density of Germanium. (5.32 g/mL) 5. Element 114 (Fl) was discovered in 1998, and it seems to be very similar to lead. It is not stable, so no tests have been run on it to determine its density. Go back to your graph and label where it should be, and from the graph predict what you think the density will be. (you may need to extend the line on your graph) 6. Write the configuration for Fl.

Conclusion: Write a brief conclusion that describes if the density of the group 14 elements follows the periodic law, and if you were successful predicting the density of Ge. Include a % error and a possible error.