Objective
To compare physical properties (mass, volume, and length) of bean market classes.
Introduction
In this lab you will learn how to collect scientific data and how to organize and present them so that they can be easily understood and interpreted. You will be given market classes of beans to compare their mass, volume, and length. Each group will work with one bean market class. You will be required to report the raw data and make it available to the other groups in the class.
Materials
- 100 g digital scale
- 100 ml measuring cylinder
- Weigh boat
- Water
- Vernier caliper
- Black beans (labeled as Rep 1 and Rep 2)
- Light red kidney beans (labeled as Rep 1 and Rep 2)
- Pinto beans (labeled as Rep 1 and Rep 2)
- Navy beans (labeled as Rep 1 and Rep 2)
- Lima beans (labeled as Rep 1 and Rep 2)
Procedure
Seed Mass
- Count out 20 seeds of the bean class assigned to your group
- Place weigh boat on the digital scale and tare (zero) the scale
- Place the seeds in the weigh boat and record the total weight in grams
- Calculate the average weight per 20 seeds
- Repeat the test (with 20 different seeds)
- Average the two repetitions and record your findings in the table below
Seed Length
- Collect a Vernier caliper
- Use the caliper to measure the length of 20 seeds of the market class that you were assigned
- Calculate the average length per seed
- Record your findings in the table below
Seed Volume
- Collect a 100 ml measuring cylinder
- Fill it to the 50 ml mark with water
- Add 20 seeds to the cylinder
- Record the change in volume
- Calculate the average volume of 20 seeds
- Repeat the test (with 20 different seeds)
- Average the two repetitions and record your findings in the table below
Raw Data Table
Black Bean Rep 1 | Black Bean Rep 2 | Light Red Kidney Rep 1 | Light Red Kidney Bean Rep 2 | Pinto Bean Rep 1 | Pinto Bean Rep 2 | Navy Bean Rep 1 | Navy Bean Rep 2 | Lima Bean Rep 1 | Lima Bean Rep 2 | |
Average Seed Wt. (g) | ||||||||||
Average Seed Lth. (mm) | ||||||||||
Average Seed Vol. (ml) |
Lab Questions (37 points)
- Add all your data and the data from the other groups in the table above (5 points)
- Why do scientists repeat their experiments, as you did in this lab? (2 points)
- How confident would you be in the average seed weight of a bean market class if you measured 2 seeds instead of 20? More or less confident? Explain why. (5 points)
- Create three bar graphs using excel, showing the (1) average seed weight versus bean market class (2) average seed length versus bean market class, and (3) average seed volume versus bean market class. Make sure to have the bean market classes on the x-axis for each graph. Also, to earn full points, ensure that both axes are labeled properly. Note: You must average Rep 1 and Rep 2 values in the table and present only one bar graph for each bean market class (15 points)
- Write a brief summary of what you discovered in this experiment, including a statement of conclusion. (10 points)