Asia-Pacific Forum on Science Learning and Teaching, Volume 17, Issue 2, Article 6 (Dec., 2016) |
A sample laboratory activity within the traditional LASE-I course
Title: Determining density of a solid object having an irregular shape
Aim: To determine density of a solid object having an irregular shape
The outcomes of lesson: Understanding density concept
Materials: An irregular solid object, 100 mL graduated cylinder, balance
Procedure:
- Measure and record the mass of the irregular solid object.
- Add 50 mL water to the graduated cylinder.
- Record the initial volume V1 of water.
- Carefully place the object to the graduated cylinder.
- Record the final volume V2 of water plus object
- Calculate the density of irregular solid object.
Conclusion:
Density of the irregular solid object =
The laboratory activity intervened within the R-LASE-I course
Title: Is Ayse’s wristlet made of pure gold or imitation?
Aim: To provide students with a way to actively participant practical activityassociated with learning density as which is one of the distinguishing properties of matter by emphasizing some science process skills.
The outcomes of lesson: Understanding density concept and applications of it, and applies this concept to interpret and analyze phenomena. Developing and understanding science processes used to gather and organize data and applies them to explore and describe objects and events in the environment.
(A scenario was given)
Is Ayse’s wristlet made of pure gold or imitation?
One of the friends Ayse’s gave her a wristlet as birthday present. Ayse wonders whether the wristlet is made of pure gold or imitation. Can you help Ayse to figure out?
(First, content knowledge of science was discussed with class. For example: What is a pure substance? What is a mixture? How do you know whether a matter is pure or mixture? What are the distinguishing properties of a pure matter? Think about what you can do with the materials given to help Ayse? How can one test for purity of a matter? Find ways to figure out density of a matter which does not have a certain geometric shape and dissolve in water. Design a measurement procedure and obtain a value of a derived quantity (density). Explain how you can use these data for determining the purity of matters.)
Materials: Wristlet, water, 100 mL graduated cylinder, balance
(The research question was discussed with class before it was presented)
Research question: How can I figure out whether Ayse’s wristlet is made up of pure gold?
(The purpose of experiment was discussed with class before it was presented)
Purpose of the experiment: To determine the density of a matter and use the data for evaluating that whether the matter pure or mixture; to understand and use science processes to gather and organize data of the density, and to apply this knowledge to explore and describe objects and events in the environment.
(A hypothesis was asked)
My hypothesis is:
(It was discussed with class about what data we need to obtain in order to figure out whether the wristlet is made up of pure gold or not. Next, an opportunity was allowed to find their own procedure for their experiments in written, and then a copy was given -bold added for emphasis on outcomes of SPS-)
Procedure:
- Measure and record the mass of wristlet on the table.
- Add 50 mL water to the graduated cylinder, and record the initial volume V1 of water.
- Carefully place the wristlet to the graduated cylinder.
- Observe carefully the final volume of water and record all your observations.
- Record the final volume V2 of water plus the wristlet on the table.
- Calculate and record the difference between the initial volume and the final volume of water.
- Calculate the density of the wristlet.
- Repeat above steps for 3 times and find an average data.
- Record the density of gold from resources on the table and compare it to established value.
- Make a decision whether the wristlet is made up of gold or not.
- Present evidence of your decision.
- Evaluate your hypothesis.
- Compare the data with class.
- Discuss sources of error.
My observations: (Please write all your observations in detail)
(Table was given to record their data)
Table 1. Data related to the wristlet
TrialMass of
the wristlet (g)Difference of the level water (cm3) (Vfinal-Vinitial)
Volume of the wristlet (cm3)
Calculate of the density
(g/cm3)Density of pure gold
Average
(It was discussed with class on how to analyze the data)
My decision: ..................
My evidence: .................
Conclusion: ………………
My hypothesis is (not) supported ……………………….
Sources of error may be ……………………….
(Discussion after the experiment: What were the most difficult aspects of conducting this experiment? What would you do differently in conducting an experiment on how we can use density property for determining that a matter is pure or mixture with together your own students in future?)
Copyright (C) 2016 EdUHK APFSLT. Volume 17, Issue 2, Article 6 (Dec., 2016). All Rights Reserved.