Solids, Liquids and Gases, Oh My!

Lesson Content

• Lesson Plan Template:

  General Lesson Plan

• Learning Objectives: What should students know and be able to do as a result of this lesson?

  
  

  After this lesson students will be able to:

  • explain why the addition of heat causes an increase in temperature.
  • define temperature as the measurement of the speed of molecules in a substance.
  • explain that during a phase change the temperature remains the same as the water molecules gain energy for the next phase, e.g. boiling water and evaporating water vapor
  • construct a time vs. temperature graph showing the curve generated from the data collected during a phase change

• Prior Knowledge: What prior knowledge should students have for this lesson?

  
  

  Students prior knowledge:

  • familiarity with water cycle
  • lab safety procedures
  • adding heat causes solids to change
  • gases are less dense than solids
  • kinetic energy is the energy of tiny particles in motion
  • heat and temperature are related
  • familiarity with basic paragraph structure
  • lab team assignments, who does what
  • can describe the information presented in a x and y axis graph

• Guiding Questions: What are the guiding questions for this lesson?

  
  

  Guiding questions:

  • What is temperature and how do we experience it?
  • How do we measure it?
  • What happens to the particles of a substance as it undergoes a phase change?

• Teaching Phase: How will the teacher present the concept or skill to students?

  
  

  The the concept will be presented in the following fashion by using:

  • view https://www.youtube.com/watch?v=EZHmUTmJtF8

  After the formative assessment and the short video, students will participate in a discovery lab.

  In general students do not understand that as heat is added to ice and the ice melts that the temperature will flatten when graphed to show that ice/water is undergoing a phase change and energy is being used to break the tighter bonds in the ice between the molecules.

  This is at the core of The Kinetic Molecular Theory of Matter.

  The lab goal is for students to understand what is happening: As ice melts and because of the kinetic energy--the energy of molecules moving at higher speeds-- so ice melts because the water molecules have broken their bonds. The students will see this in the change from solid ice to liquid water.

  This is the goal of the lesson and it is easy for the students to see that ice will melt and water will boil--even to the point of boiling completely away, but to understand the WHY this physically happens begs a deeper appreciation for what is occurring at the molecular level.

  To develop this understanding through the lab the teacher will ask, "What do you observe/see?" Why is that happening? How do we know that rising temperature is causing this? These questions will help the teacher check for understanding and are continuous, probing and direct.

  The progression of the lab is designed to illicit questions and responses from both teachers and students as they are guided through the phase changes.

  Student understanding of the concepts will come from following the steps of the lab, seeing what is happen and when, the WHY of the lab and how it explains how The Kinetic Molecular Theory explains the phenomenon.

• Guided Practice: What activities or exercises will the students complete with teacher guidance?

  
  

  The students will listen to this short video/song about the heating curve of water:

  https://www.youtube.com/watch?v=lTKl0Gpn5oQ

  The students will complete a lab for the heating curve of water.

  Materials list:

  • lab safety gear: apron, glasses, hair pulled back and tied
  • Six hot plates
  • six 500 ml beakers
  • crushed ice
  • ring stand/clamp for thermometer
  • 6 thermometers
  • timers
  • graph paper

  Lab Activity Sheet

  ** Review and follow all safety rules for working with heat and glassware with your students.

  Lab Activity:

  1. Students begin with a beaker 3/4 full of crushed ice. Place beaker on hot plate and adjust thermometer in clamp so that it is not touching the bottom and is about 2.5 cm (1 in.) from glass bottom. Turn hot plate to medium heat setting.
  2. Have a student time and record temperatures at 2 minute intervals.
  3. Record any other physical observations like boiling or the generation of steam.
  4. Note temperature during phase changes, e.g. when this happens and for how long.
  5. Continue until a rolling, steady boil and water is clearly evaporating.
  6. Observe for another 2 minutes.
  7. Turn off hot plate and return to tables. Allow water to cool. (it is best for teacher to pour hot water out using thermal gloves).
  8. With the graph paper provided, each student will graph the time (x) and temperature (y) from the recorded data for the heating curve.

  At the end of the activity, the teacher will ask students to explain what happened. You want to focus on what was happening to the temperature at the phase change. Students should have noticed the water would stay at a certain temperature for a longer period of time before the temperature would continue rising. Have students relate this to the phase change and why this would occur.

• Independent Practice: What activities or exercises will students complete to reinforce the concepts and skills developed in the lesson?

  
  

  Following the discussion post lab, students will write a paragraph in their notebooks explaining the heating curve of water. It should summarize their observations in the lab and describe why the heating curve looks they way it does and how temperatures remain steady between each phase change from solid ice, to liquid water and to gaseous water vapor. The paragraph should explain the terms water molecule, kinetic energy, and the phases of solid, liquid and gas as they apply to their observations in the lab and are represented in their graphed heating curve.

• Closure: How will the teacher assist students in organizing the knowledge gained in the lesson?

  
  

  Students will complete the following short questions to summarized their thoughts after the lesson:

  • List 3 things that you learned about phase change.
  • List 2 two important features of the time vs. temperature graph for phase change.
  • Name the 1 theory that describes the motion of the particles during phase change.

• Summative Assessment

  
  

  Students will write a paragraph in their notebooks explaining the heating curve of water. It should summarize their observations in the lab and describe why the heating curve looks they way it does and how temperatures remain steady between each phase change from solid ice, to liquid water and to gaseous water vapor. The paragraph should explain the terms water molecule, kinetic energy, and the phases of solid, liquid and gas as they apply to their observations in the lab and are represented in their graphed heating curve.

• Formative Assessment

  
  

  Good morning/afternoon: we are going to investigate The Kinetic Molecular Theory of Heat and how heat increases the temperature of matter and how this increase affects the motions of molecules by causing them to really speed up.This increase in molecular motion (kinetic) causes physical changes that we can see. We are going to do a Bell Lab for a warm up by measuring the temperatures of tap water, warm water and ice water.

  Formative Assessment:

  Introduce key terms: molecule, kinetic energy, solid, liquids and gases.

  Have students draw picture definitions for each word using colored pencils to illustrate/draw what these words mean to them at this time. Drawing with captions and descriptions is appropriate. Post these word pictures in the classroom.

  Safety gear for the formative assessment:

  • aprons
  • safety glasses
  • hair ties for long hair

  For each lab station of four students:

  • 3 small paper cups (4 ounce)
  • one with ice and water
  • one with warm water (not boiling)
  • one with tap water
  • a thermometer

  Each lab team will measure the temperatures of the different cups of water.

  Then write them neatly in their logbooks using the simple grid on the board.

  Next, ask the students to answer the bell question: What does temperature measure?

  Encourage students to talk with their lab mates. Ask them to strive for an agree upon answer to the bell question. A few minutes later open the discussion and so, what do you think temperature measures?

  Listen as students answer, offer additional probing questions.

• Feedback to Students

  
  
  • Feedback comes from the teacher monitoring the student's performance and asking questions, e.g., what is happening to the molecule's motion as the kinetic energy from the heat continues?
  • Why do some thermometers read a little differently? How much do you think the temperature will change over time?
  • When the temperature seems to have stopped increasing, what do you think is happening to the ice at the molecular level?
  • Students are encouraged to think aloud and feel comfortable thinking openly through the class. Students will predict what a heating curve graph for water will look like and why they think it looks that way.

  The class is open ended and centered around student's developing their own learning bridge.

  Questions revolve around key terms, safety, lab procedures, student's expectations and their own questions.