(The mystery of condensation)
Purpose: Students will participate in scientific inquiry, proposing hypotheses, creating and conducting experiments, and reaching conclusions about the often-unknown phenomenon of condensation. (The phase change of a substance from its gas state to its liquid state.) The condensation of water will be explored.
** Before doing this activity or during the duration of this activity students should be given an understanding of the process of scientific inquiry (the scientific process). This activity can also be used as an introduction into the topic of phase changes (the changes between solids, liquids, and gases). Included in the lesson plans are suggested content that can be taught for each day of the activity. Students’ knowledge of the suggested concepts is crucial for their success and understanding of this activity. (Remember this could be taught prior to or during the course of the activity) If you decide to teach the material throughout this activity, use the first part of the class each day to teach the material, and the remaining time for the activity. This activity is designed to be completed over 4 class periods, each lasting 40-50 minutes.
Standards Covered:
5.1.2 Begin to evaluate the validity of claims based on the amount and quality of the evidence cited.
5.2.4 Keep a notebook to record observations and be able to distinguish inferences from actual observations.
5.2.6 Write instructions that others can follow in carrying out a procedure
5.3.8 Investigate, observe, and describe that heating and cooling cause changes in the properties of materials, such as water turning into steam by boiling and water turning into ice by freezing. Notice that many kinds of changes occur faster at higher temperatures.
5.3.9 Investigate, observe, and describe that when warmer things are put with cooler ones, the warm ones lose heat and the cool ones gain I until they are all at the same temperature. Demonstrate that a warmer object can warm a cooler one by contact or at a distance.
6.1.2 Give examples of different ways scientists investigate natural phenomena and identify processes all scientists use, such as collection of relevant evidence, the use of logical reasoning, and the application of imagination in devising hypotheses and explanations, in order to make sense of the evidence.
6.2.8 Analyze and interpret a given set of findings, demonstrating that there may be more than one good way to do so.
8.2.6 Write clear, step-by-step instructions (procedural summaries) for conducting investigations, operating something, or following a procedure.
Possible Standards Covered:
5.2.8 Recognize when and describe that comparisons might not be accurate because some of the conditions are not kept the same.
7.1.4 Describe that different explanations can be given for the same evidence, and it is not always possible to tell which one is correct without further inquiry.
7.6.2 Understand and explain that Louis Pasteur wanted to find out what caused milk and wine to spoil. Note that he demonstrated that spoilage and fermentation occur when microorganisms enter from the air …
8.1.3 Recognize and describe that if more than one variable changes at the same time in an experiment, the outcome of the experiment may not be attributable to any one of the variables.
Suggested Materials:
(It depends on the students’ creativity with solving the problem!!)
- Cups or beakers
- A bag of ice
- Food coloring
- Thermometers
- Etc…
Day 1: I Introductory Material
Suggested Teaching Material: (Day 1)- All material can exist in three different states: as a solid, liquid, or gas.
- (Phase Changes) to change a material from a solid to a liquid or from a liquid to a gas the temperature of that material must be raised; and vice-versa. (To change a gas to a liquid, or a liquid to a solid the temperature of the material must be lowered)
- (The Warming or Cooling of Objects) When an object with a high temperature, is placed next to, or in contact, with an object at a lower temperature. The temperature of the warmer object will go done and the temperature of the cooler object will be raised until they are at the same temperature.
- Fill a 600ml beaker with 200ml of warm water and a 250ml beaker with 200ml of cold water.
- Have the students use a thermometer to measure the temperature of each beaker of water.
- Place the 250ml beaker into the 600ml beaker of water so that it is floating in the warm water.
- Place a thermometer in each beaker and have the students note what happens to the temperature of the water in each beaker.
- Leave the setup alone for the rest of the period and have the students measure the temperature of each beaker at the end of the period.
- Discuss the observations with the class.
- (Optional advanced topic) The relationship between the change in temperature of an object and the change in average internal energy of the object.
If energy is added to a material the atoms or molecules begin to vibrate more rapidly and the temperature increases.
(Vice-Versa) If energy is taken away from a material the atoms or molecules move or vibrate at a slower rate and the temperature of the material decreases.
*** An additional day or two may be required to teach the material ***
Day 2: Learning about Science Inquiry
Introductory Activity:
At the beginning of class, leave a glass or container of very cold water on a desk and leave it untouched for the entire period. Near the end of class, ask the students to observe the glass and the water collected on the desk. Ask them to think about these questions: (Do not provide answers!)
- Where did the water (on the desk) come from?
- Does this cup/beaker have a leak?
- What causes this to happen?
Suggested teaching material: (Day 2)
- The Scientific Process- certain process that all scientists use to make sense of the world around them.
- Observation – noticing things about the world around us and gathering relevant evidence and information about those things.
- Hypothesis – “an informed guess or tentative explanation for which there is not yet much evidence.” (Indiana State Standards)
- Experimentation – a controlled event to determine whether a hypothesis is true or false.
- Conclusion – a statement about the truth or falsehood of the proposed hypothesis.
(EXAMPLE) Cafeteria Science
A student in the cafeteria sits down to eat his/her lunch for the day, provided by the school. He/she observes that the lasagna looks a little strange today. Based on the observation that the lasagna looks a little weird he/she guesses that it’s not going to taste very good (a hypothesis is made!). He/she attempts a single experiment, a bite of the menacing lasagna, and finds to his/her surprise that it actually tastes good! Based on the experiment, the single bite, he/she reaches the conclusion that it doesn’t taste bad.
Ask the students if they can give examples of when they have used the scientific process.
Day 3: Hypothesizing and Experimental Design
Suggested teaching material: (Day 3)- Review the basic components of the scientific process
- Discuss the following historical example showing how scientists have used the scientific process to challenge current held hypotheses and make new discoveries about the world around them.
Early scientists believed that living things could come from non-living things. (Examples: flies from rotten meat, mice from wheat, etc…)
Explain how Francesco Redi (1668) tried to disprove the theory of spontaneous generation through the first controlled experiment.
(His hypothesis was that flies do not spontaneously generate from meat. For an experiment he placed raw meat in several jars. Some jars he covered, some he simply left uncovered. He then observed the jars over several days and found that only flies were produced in the meat in the uncovered jars. His conclusion was that the theory of spontaneous generation is false.)
Have the students discuss how Redi’s experiment showed that the theory of spontaneous generation is false.
Discuss what a controlled experiment is, and why Redi’s experiment was considered a controlled experiment.
Explain that unless an experiment is controlled, a conclusion cannot be reached. It is required to reach a cause-effect relationship (More advanced idea: the need for only one independent variable and one dependent variable.)
For more material on the topic visit the following website:
)
- (Optional advanced topic) Describe Louis Pasteur’s contribution to science. He put to death the persistent theory of spontaneous generation: the idea that spontaneous generation could not produce large living things, but that it could produce very small living things like bacteria. (Read information found at above web link.)
(Activity)
- Have the students get into groups to discuss the questions that were presented about the water glass demonstration.
- Have each group write down several hypotheses explaining where the water came from, and what caused the water to collect on the outside of the cup and the table.
- Compile a list of hypotheses on the chalkboard from each group and have the class decide which are the most probable.
- Assign each group one hypothesis. Tell them they have to come up with an experiment to determine whether their hypothesis is true or false. (Tell them the experiments must be done using simple materials, or any material that you can easily get.)
- Have each student record: (On the Experimental Design Worksheet)
- How to conduct their experiment
- What they are trying to figure out
- What results will show that their hypothesis is true and what results will show that their hypothesis is false
- The materials they need to do the experiment
(Possible Students’ Hypothesis and Subsequent Experiments :)
- (Hypothesis) The water came from the water in the cup.
→ (Experiment) Place a cold, empty, dry cup on the desk to see if it collects water. (Cool the cup
→ (Experiment) Add food coloring to the water in the glass and observe the color of the collected water on the outside of the glass.
- (Hypothesis) Because the glass was cold, water collected on the outside of it.
→ (Experiment) Place 2 identical glasses on a desk, one with warm water, one with cold water, and see if it makes a difference.
Day 4: Conduct Experiments and Make Conclusions
- Using the Experimental Design Worksheet, have the students set up and conduct their experiments according to what they had previously planned.
- Have them record the results of their experiment (What happened?)
- Based on their results have the students talk about and write down if their hypothesis was true or not. (Why or why not)
- Have each group present to the class the conclusion they reached about the appearance of the mysterious water.
- As a “scientific community”, have the students determine, based on all of the evidence, where the water came from, and how it got there.
**They may not be able to answer the questions completely, based solely on the results of their experiments. Explain that sometimes, like in science, to fully understand certain things, further hypotheses must be made, and experiments must be done. This is the continual process that allows us to try to describe the world around us! **
Note: Air conditioned buildings may cause the effect of condensation on cold objects to be diminished. First, test out the demonstration before you do it in front of the class. If the air in the building is too dry, try doing the demonstration and subsequent experiments outside, where there is more moisture in the air.
Author: Aaron Debbink
Experimental Design Worksheet Period:______
Name: ______
Hypothesis: ______
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Materials Needed: ______
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Description of Experiment: ______
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Results that will show that your hypothesis is FALSE:
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Results that will show that you hypothesis is TRUE:
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