PhET-Simulations-for-Physics/C2/States-of-Matter/English-timed

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Time Narration
00:01 Welcome to this spoken tutorial on States of Matter Simulation.
00:06 In this tutorial, we will learn about States of Matter, an interactive PhET simulation.
00:13 To follow this tutorial, learners should be familiar with topics in high school science.
00:20 Here I am using-

Ubuntu Linux OS version 14.04

Java version 1.7.0

Firefox Web Browser version 53.02.2

00:37 Using this Simulation, students will be able to:

1. Describe the characteristics of states of matter.

2. Predict how change in temperature or pressure changes the behavior of particles.

3. Study melting, freezing and boiling points of different substances.

00:58 4. Compare particles in three different phases.
01:02 5. Compare interactions between particles in solids, liquids and gases.
01:09 6. Study the relation between temperature and kinetic energy of molecules.
01:15 Matter around us exists in 3 states- solid, liquid and gas.
01:22 These states arise due to intermolecular forces between the particles.

Change of state occurs on the application of heat and pressure.

01:34 Now let us begin the simulation.
01:37 Use the given link to download the simulation.

http://phet.colorado.edu

01:42 I have already downloaded States of Matter simulation to my Downloads folder.
01:49 To open the simulation, right click on States-of-Matter html file.

Select Open with Firefox Web Browser option.

02:00 File opens in the browser.
02:03 The simulation opens with 3 screens-

States, Phase changes and Interaction.

02:13 Click on States screen.
02:16 Screen has a container filled with Neon atoms, by default.
02:22 The container is also fitted with a thermometer.

It shows the temperature in Kelvin scale.

Click on the black arrow to see the temperature in Celsius scale.

02:36 Below the container, there is a heat regulator to Heat or Cool the system.
02:43 Drag and hold the slider up to heat the container.

Drag and hold the slider down to cool the container.

02:53 On the right-side of the screen, there is a list of Atoms & Molecules.
02:59 Below this list, there are buttons for Solid, Liquid and Gas.
03:07 There are two buttons at the bottom-left corner of the simulation.

Bigger button to pause and play the simulation.

03:16 The smaller one to play the simulation step-wise.

Reset button is at the bottom-right corner.

03:25 Here, we can heat or cool the atoms or molecules to see the phase change.
03:32 Container has Neon atoms. Click on Solid button.
03:38 Observe the screen. In solid, Neon particles are tightly packed.
03:43 The movement of atoms is restricted. The vibrations are minimum.
03:50 Increase the temperature by moving the slider up on the heat regulator.
03:56 Increase the temperature up to 27 K. we can see movement in the atoms.
04:04 It indicates that Neon is in liquid state.

Increase the temperature further. The atoms are moving freely in the container.

04:15 Neon is in gas phase.
04:18 In the gas phase, atoms move randomly with high speed.
04:24 Due to this random motion, atoms hit each other and walls of the container.
04:30 Click on Reset button to reset the simulation.
04:35 Select Water molecules from the list.

Click on Solid button.

04:41 Observe the temperature and movement of molecules in the container.

Again click on Liquid button and observe molecules in the container.

04:53 Similarly click on Gas button.

Click on Reset button to reset the simulation.

05:01 Next, click on Phase Changes screen at the bottom of the interface.
05:08 Using this screen, we can explore how the atoms or molecules behave, when the system is heated, cooled, compressed or when more atoms are added.
05:20 In this screen, the container is fitted with a pressure gauge.
05:25 It is also fitted with a pump, to pump in gas atoms or molecules.
05:32 On the right-side of the screen we can see-

1. The Interaction Potential curve or the Lennard-Jones potential curve and

2. Phase Diagram curve.

05:44 Before you begin the experiment, note the initial pressure on the pressure gauge.
05:51 Note the temperature on the thermometer.

Neon is in solid state, as denoted by a red dot on the Phase Diagram.

06:02 Increase the pressure by pushing the finger down slowly.

Click on finger, hold the mouse and drag down slowly.

06:13 Observe the temperature and pressure as the lid touches the molecules.
06:19 As pressure increases, kinetic energy of molecules increases.

Observe the red dot on the Phase Diagram.

06:28 Add more Neon atoms to the container by pushing the pump.
06:43 As the collisions between particles increases, temperature and pressure increases.

Observe the Phase Diagram, Neon is now in gas phase.

06:55 At this point, if you increase the pressure the lid blows off.

This allows some of the atoms to escape out of the container.

07:06 To replace the lid, click on yellow Return Lid button.
07:11 Drag the temperature regulator down to cooling position.
07:16 The temperature of the container now decreases.

Neon is now in liquid state.

Observe the pressure gauge, pressure also decreases.

07:28 Cool the container until the phase changes to solid.

Keep track of the red dot on the Phase Diagram.

07:39 Similarly observe the phase change for other Atoms and Molecules in the list.
07:49 Click on the Interaction screen at the bottom of the interface.
07:54 This screen shows a plot of Potential Energy versus Distance Between Atoms.
08:01 Using this screen, we can show the relation between bonding distance and stability.
08:08 Click and drag the atoms to separate them.

Drag the movable atom away from pinned atom.

08:17 Observe the Potential Energy curve as the atoms come closer.

Potential energy varies when attractive and repulsive forces change between atoms.

08:29 As an assignment:
08:31 In Phase Changes screen, select Adjustable Attraction from Atoms & Molecules list.
08:38 Use the slider to change Interaction Strength from weak to strong.

And, study the effect of temperature and pressure on these molecules.

08:50 Using Phase Changes screen, determine which substance has strongest inter atomic or molecular forces.
08:59 In this tutorial, we have learnt: how to use States of Matter interactive PhET simulation.
09:07 Using this simulation, we have learnt about-

1.Characteristics of States of matter.

09:14 2. How variation in temperature or pressure changes the behavior of particles.
09:21 The video at the following link summarizes the Spoken Tutorial project. Please download and watch it.
09:30 The Spoken Tutorial Project team conducts workshops using spoken tutorials and gives certificates on passing online tests.

For more details, please write to us.

09:45 Please post your timed queries in this forum.
09:51 This project is partially funded by Pandit Madan Mohan Malaviya National Mission on Teachers and Teaching.
10:00 Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.

More information on this mission is available at this link.

10:14 This tutorial is contributed by Snehalatha Kaliappan and Meenal Ghoderao. Thank you for joining.

Contributors and Content Editors

Nancyvarkey