PhET/C3/Radioactive-Dating-Game/English

Visual Cue	Narration
Slide Number 1 Title Slide	Welcome to this tutorial on Radioactive Dating Game, an interactive PhET simulation.
Slide Number 2 Learning Objectives We will demonstrate, Radioactive Dating Game PhET simulation	In this tutorial, we will demonstrate, Radioactive Dating Game, an interactive PhET simulation.
Slide Number 3 System Requirements Ubuntu Linux OS version 16.04 Java version 1.8.0 Firefox Web Browser version 60.0.2	Here I am using, Ubuntu Linux OS version 16.04 Java version 1.8.0 Firefox Web Browser version 60.0.2
Slide Number 4 Pre-requisites	Learners should be familiar with high school physics and chemistry.
Slide Number 5 Learning Goals Using this simulation, we will look at Radioactive decay and half life Decay rates Measurement of radioactivity Radioactive dating	Using this simulation, we will look at Radioactive decay and half life Decay rates Measurement of radioactivity Radioactive dating
	Please refer to the additional material provided with this tutorial. Let us begin.
Slide Number 6 Link for PhET simulation http://phet.colorado.edu	Use the given link to download the simulation. http://phet.colorado.edu
Point to the file in Downloads folder.	I have already downloaded the Radioactive Dating Game simulation to my Downloads folder.
Open the terminal by pressing Ctrl+Alt+T simultaneously.	To open the jar file, open the terminal.
At the terminal prompt, type cd Downloads and press Enter.	At the terminal prompt, type cd Downloads and press Enter.
Type java space hyphen jar space radioactive-dating-game_en.jar.	Type java space hyphen jar space radioactive-dating-game_en.jar.
Point to the browser address.	File opens in the browser in html format.
Cursor on the interface.	This is the interface for the Radioactive Dating Game simulation.
	Now we will explore the interface.
Point to four screens in the interface.	The interface has four screens: Half Life Decay Rates Measurement Dating Game
Show the Half Life screen.	We are already looking at the Half Life screen.
Point to the graph at the top of the screen. Point to units of time along the x-axis.	At the top of the screen is an Isotope versus Time graph. Pay attention to the units of time.
Show Choose Isotope panel to the right. Point to the three options in Choose Isotope panel.	On the right side of the screen, you see a Choose Isotope panel. It has three options showing unstable nucleus decaying to stable nucleus.
Point to the Bucket o’ Atoms in the simulation panel. Point to the C-14 atoms in the bucket and to the default selection of C-14. Point to the “Add 10” button attached to the bottom of the bucket.	In the middle is the simulation panel containing a Bucket o’ Atoms. Note that it contains C-14 atoms as the default selection is C-14. Attached to the bottom of the bucket is a button called “Add 10”.
Slide Number 7 Stable and Unstable Nuclei Electrostatic repulsion between protons in nucleus Strong nuclear force ~ binding energy High binding energy; stable nucleus Low binding energy; unstable nucleus ~ radioactive	Stable and Unstable Nuclei There is electrostatic repulsion between positively charged protons inside the nucleus. The strong nuclear force overcomes this electrostatic repulsion between protons. The energy associated with this force is the binding energy. The lower the binding energy, the more unstable is the nucleus. Such an unstable nucleus is said to be radioactive.
Point to Play/Pause button and Step button next to it.	Below this simulation panel is a Play/Pause button and a Step button next to it.
Point to blue Reset All Nuclei button in simulation panel.	In this simulation panel is a blue Reset All Nuclei button. This button lets you return to the start but with the selected isotope.
Point to the white Reset All button below the right panel.	Below the right panel is a white Reset All button. This button resets the simulation in this screen to all the default settings.
Point to the default Isotope selection of C-14 to N-14.	The default Isotope selection is C-14 to N-14.
Point to the Isotope versus time graph. Point to vertical red dashed line labeled Half Life near the 5000 year mark.	Observe the Isotope versus time graph. There is a vertical red dashed line labeled Half Life near the 5000 year mark. The half-life of C-14 is 5730 years.
Point to red C-14 symbol above the blue N-14 symbol along the y-axis.	Along the y-axis, you can see the red C-14 symbol above the blue N-14 symbol. C-14 atoms will appear in the upper row and N-14 atoms in the lower one.
Point to the red circle to the left of the Isotope label. Point to hash symbols on the left of the circle.	To the left of the Isotope label is a red circle. Numbers of C-14 and N-14 atoms shown by hash symbols will appear to the left of the circle.
Slide Number 8 Radioactive Decay Alpha decay Beta decay Gamma decay Half-life	Radioactive Decay is the spontaneous conversion of an unstable nucleus into a stable nucleus. It involves the release of subatomic particles and their energy as radiation. It is of the following types: Alpha decay Beta decay Gamma decay Half-life is the time taken for half of the nuclei in a radioactive material to decay.
	Let us get back to the simulation.
Click on Add 10 and immediately click on the Pause button.	Click on Add 10 and immediately click on the Pause button.
Point to the 10 C-14 atoms added to the simulation panel. Almost immediately, red C-14 has started to decay to give blue N-14.	Ten C-14 atoms have been added to the simulation panel. Almost immediately, red C-14 has started to decay to give blue N-14.
Keep clicking on Step button to the right of Pause.	Keep clicking on Step button to the right of Pause.
Show the red C-14 atoms flying across the graph in the upper row. Show the blue N-14 atoms in the lower row.	Observe the red C-14 atoms moving across the graph in the upper row. In the lower row, blue N-14 atoms appear as the C-14 atoms decay.
Point to the circle changing to blue.	Note how the circle changes to blue as more N-14 atoms form.
Keep clicking on Step button to the right of Pause until the circle is half red and half blue.	Keep clicking on Step button to the right of Pause until the circle is half red and half blue.
Point to 5 blue N-14 atoms on the left of the dashed half-life line.	Observe that, in the graph, there are 5 blue N-14 atoms on the left of the dashed half-life line. Out of 10 C-14 atoms, half of them took 5730 years to decay into 5 N-14 atoms.
Point to 5 C-14 and N-14 atoms in the simulation panel.	Observe that there are 5 C-14 atoms and 5 N-14 atoms in the simulation panel also. This is the definition of half-life.
Click on Step button until you have 7 N-14 and 3 C-14 atoms.	Click on Step button until you have 7 N-14 and 3 C-14 atoms.
Point to the 2 N-14 atoms between the red dashed line and the 10000 mark.	Another 5730 years are taken for the remaining 5 C-14 atoms to decay to 2.5 N-14 atoms. We see 2 N-14 atoms between the red dashed line and the 10000 mark.
Point to Add 10 button and to the bucket.	If you click again on Add 10, another 10 C-14 atoms will be added to the simulation panel. In this way, you can keep clicking Add 10 until the bucket is empty.
	Predict the number of C-14 atoms remaining after different periods.
Perform the same simulation for the other nuclei.	Perform the same simulation for the other nuclei.
Click on the Decay Rates tab to go to that screen. Show the interface.	Click on the Decay Rates tab to go to that screen. The interface has a similar arrangement as the Half Life screen. Please explore this screen in the same way.
Click on the Measurement tab.	Now, let us click on the Measurement tab to go to that screen.
Point to Tree, the default selection under Choose an Object on the right.	In the right panel, under Choose an Object, we will stay with Tree, the default selection.
Point to Carbon-14, and Objects under Probe Type in top left.	In the top left, under Probe Type, we will retain the default selections, Carbon-14, and Objects.
Click on Plant Tree button in the bottom right corner. Point to the tree growing right where the probe is placed.	Click on Plant Tree button in the bottom right corner. Observe that a tree grows right where the probe is placed.
Immediately click on the Pause button.	Immediately click on the Pause button.
Point to 100% seen above Probe Type in the upper left corner.	Observe 100% appear above Probe Type in the upper left corner.
Keep clicking on the Step button to the right of Pause to move the simulation along.	Keep clicking on the Step button to the right of Pause to move the simulation along.
Point to red line moving at the top of the graph along 100%.	Note that a red line moves at the top of the graph along 100%.
Show % of C-14 above the graph.	Above the graph, % of C-14 is the default selection.
Point to the white box below the graph.	The white box below the graph shows the number of years since the tree was planted.
Point to the red line at the top of the graph.	The red line shows % of C-14 remaining in the tree after those years after it was planted.
Click on the second C-14 to C-12 ratio radio button above the graph.	Click on the second C-14 to C-12 ratio radio button above the graph.
Point to the red line at the top of the graph.	Now the red line shows the C-14 to C-12 ratio in the tree after those years of planting it
Click again on the % of C-14 radio button above the graph.	Click again on the % of C-14 radio button above the graph.
Point to % in the top left, the tree and the white box below the graph.	Keep track of the % in the top left, the tree and the number of years below the graph.
Note down the number of years and % of C-14 when the tree Loses its green color Loses all its leaves Falls over	Note down the number of years and % of C-14 when the tree Loses its green color Loses all its leaves Falls over
Click on the Play button and let the simulation run until you see 55% above Probe Type.	Click on the Play button and let the simulation run until you see 55% above Probe Type.
Keep clicking on the Step button until you see 50% in the top left window.	Keep clicking on the Step button until you see 50% in the top left window.
Point to the tree and the number of years in the white box.	Observe the tree and the number of years seen below the graph.
Point to 50% on y-axis, to red line and to x co-ordinate.	Note the number of years after which you see 50% of C-14 in the tree.
Click on the C-14 to C-12 ratio radio button above the graph.	Click on the C-14 to C-12 ratio radio button above the graph. Observe that this ratio has also dropped to half of what it was when the tree was planted.
Slide Number 9 Other Measurements Select Rock and Uranium-238 Objects selection Probe → volcano → Erupt Volcano When do you see 50% U-238 in cooled volcanic rock? Half-life of U-238 is 4.5 billion years Air radio button (probe in air)	Choose the options shown here to carry out other measurements.
Click on the last Dating Game tab. Show the interface.	Let us click on the last Dating Game tab to go to that screen. We can measure the levels of C-14, U-238 or other custom nuclei in this screen. We see objects on and below the ground on which we can place the probe to measure these levels.
Slide Number 10 Radioactive Dating Two isotopes of C: 12C and 14C Both isotopes → CO2, living organisms 14C → 14N, 14C:12C organisms ~ atmosphere	Radioactive Dating Carbon has two isotopes: C-12 and C-14. Both are converted to carbon dioxide and are taken in by living organisms. C-14 decays to N-14 but the ratio of C-14 to C-12 remains same in organisms and the atmosphere.
Slide Number 11 Radioactive Dating-Cont’d Death of organism, ratio and 14C fall Radioactive dating, 14C:12C of sample vs recently dead specimens Ur-Pb dating for rocks, artefacts etc	Radioactive Dating-Continued When an organism dies, it no longer takes in any carbon. So levels of C-14 and ratio of C-14 to C-12 fall. Radioactive dating compares C-14 C-12 ratio of sample to recently dead specimens. It estimates how long the organism has been dead. Uranium-lead dating is used for rocks, archaeological artefacts etc
Point to the graph on the top. Point to the two radio buttons, % of C-14 and C-14 to C-12 ratio, for the y-axis. Point to the x-axis. Point to the vertical red dashed line.	On the top, we see the graph. As before, we have two radio buttons, % of C-14 and C-14 to C-12 ratio, for the y-axis. x-axis gives time in years. The vertical red dashed line is the half-life.
Point to these default selections: Under Probe Type, Carbon-14 Objects % of C-14	Let us keep the following default selections: Under Probe Type, Carbon-14 Objects % of C-14
Drag the probe and place it on the animal skull on the ground, to the left.	We will drag the probe and place it on the animal skull on the ground, to the left.
Point to the pop-up box next to the skull. Show the text, “Estimate age of Animal Skull”. Show the empty box and “yrs” next to it.	Observe a pop-up box that appears next to the skull. We see the text, “Estimate age of Animal Skull” and below that an empty box and “yrs” next to it.
Point to the Check Estimate button.	Below this is a Check Estimate button.
Show 98.2% in the top left side, above Probe Type.	Observe that in the top left side, above Probe Type, we see 98.2%.
Drag the double-headed green arrow to the left. Show 98.2% in the white box above the arrow.	Let us drag the double-headed green arrow above the graph. In the white box above the arrow, % of C-14 should be approximately 98.2%.
Show t = 123 yrs in the white box below % of C-14.	Observe that it equals 123 yrs appears in the white box below % of C-14. So after 123 years, approximately 98.2% C-14 is left in the animal skull.
Type 123 in the empty box below Estimate age of Animal Skull. Click Check Estimate button.	Type 123 in the empty box below Estimate age of Animal Skull. Click Check Estimate button.
Point to green text-box with 123 years in its place with a green smiley face next to it.	The Estimate pop-up box disappears. A green text-box with 123 years appears in its place with a green smiley face next to it.
	We have successfully dated the animal skull by measuring the % of C-14 remaining in it.
Slide Number 12 Assignment Estimate ages of all objects in Dating Game screen Correlate age (years) with percentage of unstable nucleus Correlate age (years) with depth at which object found C-14: animal remains; U-238: rocks, objects	As an assignment, Estimate ages of all the objects in the Dating Game screen. Correlate age in years with the percentage of unstable nucleus. Correlate age in years with the depth at which the object is found. Remember to use C-14 for animal remains and U-238 for rocks and other objects.
	Let us summarize.
Slide Number 13 Summary We have demonstrated, Radioactive Dating Game PhET simulation	In this tutorial, we have demonstrated how to use the Radioactive Dating Game PhET simulation.
Slide Number 14 Summary Radioactive decay and half life Decay rates Measurement of radioactivity Radioactive dating	Using this simulation, we looked at: Radioactive decay and half life Decay rates Measurement of radioactivity Radioactive dating
Slide Number 15 About the Spoken Tutorial Project Watch the video available at http://spoken-tutorial.org/ What_is_a_Spoken_Tutorial It summarizes the Spoken Tutorial project If you do not have good bandwidth, you can download and watch it	The video at the following link summarizes the Spoken Tutorial project. Please download and watch it
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Slide Number 18 Acknowledgement	This project is partially funded by Pandit Madan Mohan Malaviya National Mission on Teachers and Teaching.
Slide Number 19 Acknowledgement	Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India. More information on this mission is available at this link.
	This is Vidhya Iyer from IIT Bombay, signing off. Thank you for joining.

Contributors and Content Editors

Madhurig, Vidhya