Chia Guo Hao Microteaching & Lesson Planning QCP521

054396H23 Melting, Boiling and Evaporation Due: 15/10/05

Appendix A

Lesson Procedures

054396H23 Melting, Boiling and Evaporation Due: 15/10/05

Time/min

/ Activities / Resources / Rationale /
5
(5) / i. Walk into class, lay cloth on teacher’s table and take out a block of ice, a crushed icemaker and a bowl. Get a student volunteer to make a bowl of crushed ice.
ii. While student is making crushed ice, announce the topic for today, melting, boiling and evaporation, by writing on the whiteboard and distribute the handout for today’s lesson.
iii. Put a thermometer into the bowl of crushed ice and ask a second volunteer, one with better grades, to take the temperature down for every 5 minutes during the lesson. (See Appendix C)
iv. PC/Laptop to be started and ready to be used for the later part of the class. / Block of ice, crushed ice maker, bowl and cloth
Whiteboard, markers, handouts
Thermometer, timer
PC/Laptop / i. Activity to capture student’s attention and to prepare for the melting ice experiment for the class.
ii. Introduce the topic that they will learn today.
iii. To let students realize that ice melts at constant temperature and use the data points in the melting curve later. The volunteer may not be able to concentrate on the lesson fully so he/she preferably has to be smarter or has better grades.
iv. The first 5 minutes is to setup and prepare the lesson for class. Alternatively, the lesson could be held in a lab with all materials ready for lesson. Then the first 5 minutes is to wait for students to arrive and settle down.
7
(12) / i. Recap on the kinetic model for matter with aid of a pictorial representation given in notes. Students will be given 3 minutes to discuss in pairs with their neighbours, the properties of solid, liquid and gas based on the picture and knowledge learnt earlier (Activity 1). They are to categorize their findings under
1. Arrangement of particles

Movement of particles

ii. At the end 3 minutes, each pair will be asked one property for either state of matter. There should be enough materials to cover 18 pairs of students at least. The answers would be summarized using OHP during the discussion and students have to copy down notes on their handouts at the same time. / Handouts, OHP / i. The kinetic model for matter can be used to describe the phenomenon of change in states. So it is a good time to let students recall what they had learnt in the past and participate in the lesson through discussions.
ii. This is also a good chance for students to warm-up for the lesson and engages their minds into thinking. Students are already exposed to model for matter so minimal time will be spent on this area.
10
(22) / i. Based on the kinetic model for matter, explain melting, highlighting the fact that temperature reminds constant for melting. Repeat the same for freezing. Ask students to recall what melting/freezing point is.
ii. Use the whiteboard to illustrate the change of state with drawings while explaining to emphasize the fact that melting occurs without any change in temperature is a result of breaking or forming of bonds during change of state.
iii. After discussion, definitions for melting and freezing will be shown via OHP for students to take down notes. / Handouts, OHP, whiteboard and markers / i. Linking the model for matter to melting and freezing in explanation is to help the students grasp and remember the definitions. Such discussions work best with audio learners.
ii. The whiteboard illustrations are helpful for visual learners to remember the definition.
iii. Finally, copying down notes are targeted to kinesthetic learners
10
(32) / i. Introduce the melting curve by using the data points collected by student volunteer since the beginning of class. The bowl of crushed ice with thermometer will be passed around the class for everyone to see when the curve is plotted.
ii. Using a laptop with MS Excel, the melting curve will be sketched together with the class on their handouts. The template for the curve will be prepared beforehand (Activity 2) (See Appendix D: Excel template)
iii. The curve will have to be labeled at strategic points according to the states of the matter present. / Bowl of melting ice with thermometer, PC/Laptop and, handouts / i. Doing actual experiment with students provides a better learning channel for visual and kinesthetic learners as compared to just explaining the process. The experiment also serves to strengthen what they had learnt about melting earlier.
ii. The use of IT helps in creating the sketch quickly and accurately. It saves time and has the novelty effect as students hardly draw graphs using computers.
iii. The use of questioning is to foster thinking among students and at the same time make sure that they are alert and paying attention in class.
10
(42) / i. Explain that boiling and condensation are transitions of states just like melting and freezing. Give students 3 minutes to discuss in pairs how to fill in the blanks in the handout regarding boiling and condensation (Activity 3).
ii. Ask individuals to share their answers with the class while going through the solutions with OHP. / OHP, handouts /

i. As boiling & condensation are processes very similar to melting and freezing. The discussion gives students a chance to synthesize both ideas together.

ii. This is a chance to gauge and see if students understand the lesson on melting.
10
(52) / i. Introduce evaporation as another process for liquid to change to vapour and compare it with boiling. A video of boiling water will be shown continuously for this segment while the bowl of melted ice used previously will be used to demonstrate evaporation process.
ii. Students will be asked to pick out 6 differences between boiling and evaporating by comparing the video and the bowl of water. The differences will be summarized with OHP for students to take note of. For this segment, the OHP will be projecting out of position to incorporate the video at the same time (Activity 4). / Handouts, OHP, Video, Laptop/PC / i. Videos and the bowl of water will be able to capture the student’s imagination better than just sketching or showing a picture of boiling water. Using multimedia approaches would also appeal to different types of learners.
ii. Posing the question to students and getting them to participate by providing answers will ensure that students are engaged in the lesson. They will also have to go through the thinking processes to compare the differences.
12
(64) / i. Molecules of matters will be represented in the form of marbles in container. Vibrating the container of marbles will simulate the molecular motion/vibration. Any marbles that escaped will be considered as “evaporated”. The same set up will be used to show how various factors can affect evaporation process. These will be demonstrated through a series of experiments – see Appendix C: Demonstrations and Microteaching for more information.
ii. Various conditions, such as size of marbles, would be varied and students will be asked how the condition relates to real liquid and predict the outcome. The demonstration will be carried out and discussion in the form of Q&A will be carried out to summarize the facts. This will be repeated for other conditions. / Handouts, OHP, Marbles, Styrofoam balls, containers, small tank, a large bottle of water. /

i. The model for matter is actually very useful in the learning of topics in thermal physics. The experiment here is to try to link the macroscopic view – thermal physics, to the microscopic view – individual atoms and molecules.

ii. It is possible to incorporate inquiry-based learning in the demonstration. Under level 2 of Herron's Inquiry Level (where Higher order thinking such as synthesis would be involved for that question.), questions like: what is needed to be done to the model if studies on how temperature affects evaporation are to be carried out, may be posted to the students.
4
(68) / 1. Students are to close all their textbooks and keep all their notes for this short summary of the day’s lesson. Students will be asked to spot the mistake in the summary and correct them. They will have to complete a simple concept map for this chapter to round up the lesson. A sample of mixed ability students will be quizzed.
2. Announce the homework details (Workbook Practice 9, due next lesson) and the topic for next lesson. Clean up any mess and bring in National Education by role modeling. Ask the students to pick up litter and start keeping Singapore clean by ensuring their classroom is clean. / OHP, handouts /

i. This is to evaluate the progress of the students and how much they manage to pick up from the 2 period lessons. If all students asked were able to spot the mistake and provide answers, it will be an indication that the students had gained the required knowledge of the topic and had managed to comprehend it.

ii. To reinforce concepts learnt; provide link to next topic and to bring in National Education by role modeling.

The ‘lesson plan’ above is being set for 68 minutes of lesson with 2 minutes for allowance. Should the lesson end before time, additional thinking questions (Appendix C) related to the demonstrations may be posted to the students.. On the other hand, it is possible to leave out one or two of the blocks for the next lesson and go straight to round up the lesson in the event that the lesson is going too slowly. This is because most components in the lesson are in blocks of about 10 minutes. As for the portion regarding microteaching, last part of the lesson could be roped in should the microteaching component planned was completed earlier than expected.

Chia Guo Hao Microteaching & Lesson Planning QCP521

054396H23 Melting, Boiling and Evaporation Due: 15/10/05

Appendix B

Handouts (Teacher’s Copy)

Handouts (Student’s Copy)

Note: For the lesson, the teacher will be using the student’s copy with either an OHP or visualizer and fill in the blanks with student’s correct answers in class. The teacher’s copy will be for reference purposes only. Both copies will be printed in transparency.

Melting, Boiling and Evaporation (Teacher’s Copy)

Activity 1: Discuss in pairs, the characteristics of solid, liquid and vapour in terms of molecular arrangement and movement in the table above. (3 minutes)

Be prepared to share your answers with the rest of the class.

Time (min)

/ 0 / 3 / 12 / 21 / 25 / 27 / 30
Temperature (oC) / -5 / 0 / 0 / 0 / 5 / 10 / 19

Activity 2: From the data collected by your friends, quickly sketch a melting curve in the space provided above and label the graph according to the labels given on the right.

Activity 3: Boiling/Condensation is similar to melting/freezing. Discuss in pairs how would you complete the blanks above by inferring from melting and freezing or otherwise. (3 minutes).

Be prepared to share you answers with the rest of the class.

Activity 4: Watch the video of a pot of water boiling and compare it to a bowl of water evaporating. Can you pick out differences between boiling and evaporation to complete the figure and table below? (3 minutes)

Be prepared to share your solutions with the class

* Boiling can occur at absence of heat source. E.g. reducing pressure. But heat source is present here.

Comparing Boiling and Evaporation

Boiling / Evaporation
Temperature /

Occurs at fixed temperature
Temperature remains constant during boiling

Occurs at any temperature
Temperature may change during evaporation

Occurrence /

Takes place within liquid

/ 3. Takes place only at exposed surface of the liquid
Bubbles / 4. Bubbles are formed / 4. Bubbles are not formed
Supply of Heat / 5. Heat supplied by energy source / 5. Heat supplied by surroundings
Process / 6. Liquid changes to vapour state quickly / 6. Liquid changes to vapour state slowly

Factors affecting rate of evaporation

Temperature / Raising the temperature of liquid increases rate of evaporation as the liquid molecules are more energetic
Humidity of surrounding / Humidity is a measure of the amount of water vapour present in the air. The higher the humidity, the more water vapour is present in air and the evaporation rates become slower
Exposed surface area of liquid / The larger the exposed surface area of the liquid, the faster the rate of evaporation will be since evaporation occurs only at the exposed surface area
Movement of air above surface of liquid / Moving air (wind) removes the molecules of liquid as soon as it escapes to become vapour thus increases the rate of evaporation
Pressure / Lower atmospheric pressure increases the rate of evaporation as it is easier for liquid molecules to escape
Nature of liquid / Different types of liquid have different properties that will affect the rate of evaporation. For example, mercury hardly evaporate at room temperature due to the high boiling point while volatile liquid such as alcohol or ether evaporates quickly

Modern Application of Evaporation

Summary of Melting, Boiling and Evaporation

In this chapter, you learned that melting, freezing, boiling and condensation are processes when matter changes from one state to another at a fixed temperature. The temperature remains constant during these processes. You also learnt that heat energy absorbed by the molecules during melting and boiling processes is used to break inter-molecular bonds while heat energy is released by the molecules during freezing and condensation when intermolecular bonds are being formed. The processes can be observed through the temperature against time graph for cooling and heating of matter.