PhET/C3/Radioactive-Dating-Game/English

From Script | Spoken-Tutorial
Revision as of 18:24, 9 January 2019 by Vidhya (Talk | contribs)

Jump to: navigation, search


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.
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 underscore en dot 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 is associated with binding energy

If binding energy is low, the nucleus is unstable and is radioactive


Stable and Unstable Nuclei

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 the 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 the simulation panel is a blue Reset All Nuclei button.

It 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.

It resets the simulation in this screen to all the default settings.

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 Radioactive Decay

Alpha decay

Beta decay

Gamma decay


Radioactive Decay

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

Slide Number 9

Half-life

Half-life is the time taken for half of the nuclei in a radioactive material to decay.

Half-life

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.

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 atoms moving across the graph in the two rows.
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. Keep clicking on Step button to the right of Pause.

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 there are 5 blue N-14 atoms in the graph.
Point to 5 C-14 and N-14 atoms in the simulation panel. There are 5 C-14 atoms and 5 N-14 atoms in the simulation panel also.

This is the definition of half-life.

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.
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.

In the bottom right corner, click on Plant Tree button.
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. Keep clicking on the Step button to the right of Pause to move the simulation along.
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.
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.
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 or Step buttons to get approximately 50% in the top left window. Click on the Play or Step buttons to get approximately 50% in the top left window.
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 Rock and Uranium-238 radio buttons. Click on Rock and Uranium-238 radio buttons.
Click on Erupt Volcano and Cool rock buttons.

Measure U-238 levels in the cooled volcanic rock.

Click on Erupt Volcano and Cool rock buttons.

Measure U-238 levels in the cooled volcanic rock.

Click on the Air radio button to compare isotope levels in objects to air levels. Click on the Air radio button to compare isotope levels in objects to air levels.
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 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

Death of organism, ratio and 14C fall

Radioactive Dating

Carbon has two isotopes: C-12 and C-14.

Both are converted to carbon dioxide and are taken in by living organisms.

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.

Slide Number 11

Radioactive Dating-Cont’d

Radioactive dating, 14C:12C of samples vs recently dead specimens

Ur-Pb dating for rocks, artefacts etc

Radioactive Dating-Continued

Radioactive dating compares C-14 C-12 ratio of samples 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. On the top, we see the graph like the ones in the previous screens.
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 “years” next to the empty box below.

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 t equals 123 yrs appears in the white box below % of C-14.
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 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

Slide Number 16

Spoken Tutorial workshops

The Spoken Tutorial Project team conducts workshops using spoken tutorials and gives certificates on passing online tests.

For more details, please write to us.

Slide Number 17

Forum for specific questions:


Do you have questions in THIS Spoken Tutorial?

Please visit this site

Choose the minute and second where you have the question

Explain your question briefly

Someone from our team will answer them

Please post your timed queries in this forum.
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