Purpose: How does density change going down a group in the periodic table?
Materials:
o balance
o 10-mL graduated cylinder
o Cupcake holder
o Lead shot (Pb)
o Silicon pieces (Si)
o Tin pieces (Sn)
o Graph paper
o Metric ruler
Procedure:
o Use the data table on the next page to record all of the measurements you obtain in this investigation.
o Start what any element sample. Check to make sure that the pieces of the sample will fit inside the graduated cylinder.
o Using a plastic weighing dish, measure out a sample of the element. The samples should mass at least 2.0 grams for silicon and tin and at least 5.0 grams for lead. Be sure to account for the mass of the dish when measuring your element samples.
o Record the mass of the element sample in the appropriate place in your data table.
o Pour about 6 mL of water into the graduated cylinder. Record the actual initial volume in your data table.
o Add the element sample to the water in the cylinder. Gently tap the side of the cylinder to release any trapped air bubbles. Record the final volume in your data table.
o Calculate the volume of the element sample by subtracting the initial volume from the final volume. Record this number in your data table.
o Carefully pour off the water, collect the wet pieces of the element sample, and dry them.
o Repeat steps 2 through 8 for the remaining two elements.
o Calculate the density of each element by dividing the mass of each element sample by its volume. Record these numbers in your data table.
Data Table
measurements Silicon(Si) Tin (Sn) Lead (Pd)
Mass of the element sample (g) 2.0 2.0 5.0
Initial volume of water (ml) 5.98 6.0 6.0
Final volume of water and element sample (mL) 6.83 6.3 6.5
Volume of element sample (cm3) 0.85 0.3 0.5
Density of element (g/cm3) 2.35 6.7 10
Questions
o Why can you assume that the change in volume in the graduated cylinder is the same as the volume of the element sample?
You can assume that the change in volume in the graduated cylinder is the same as the volume of the element sample because the volume of the sample makes the water go up, and the amount that it increases is the volume.
o Which sample had the greatest volume?
Silicon had the greastest volume.
o How does density change going down a group in the periodic table?
Densities changes by increasing when you go down a group on the periodic table.
o Use you graph to estimate the density of Germanium and carbon.
Germanium and carbon's density will increase as you go down the periodic table.
o
o What are some possible sources of error in your procedure?
Some possible source of error in our procedure was that the measurements are off and not exact.
Conclusion:
During this experiment we learned that the density of the elements increase as you go down a group on the periodic table. We learned about periodic trends also. W had a very few problems with this experiment.