Half-Life of M&Ms
Introduction
Half-life is the time required for something to fall to half its initial value. The half-life of a radioactive element is the time it takes for half of its atoms to decay into something else. M&Ms were chosen because they all have the same m mark on the on one side. In this lab you will go through predicting and counting the number of remaining "mark-side up" candies that should help understand that rates of decay of unstable nuclei and how it can be measured; that the exact time that a certain nucleus will decay cannot be predicted; and that it takes a very large number of nuclei to find the rate of decay. Purpose

To stimulate the transformation of a radioactive isotope with M&Ms over time and to graph the data and relate it to radioactive decay and half-lives. Materials and Safety

Materials
* 200 pieces of M&Ms (trademark only)
* Shoe Box
* Pen/Pencil
* Paper Towel

Safety- No safety precautions needed

Procedure
1. Count out 200 M&Ms. Place all 200 candies in the shoe box with the letter facing up 2. Cover the box and shake it vigorously for 3 sec. This is 1 time interval. 3. Remove the lid and take out any atoms (candies) that have “decayed”, that is, that are now showing lettered sides down. Record on the data table the numbers of decayed and remaining atoms. 4. Replace the cover on the box, and shake for another 3-sec time interval. Record the number of “radioactive’ atoms remaining. 5. Keep repeating time interval trials until all atoms have decayed or you have reached 30 sec on the data table 6. Repeat the whole experiment a second time, and record all data. 7. Average the number of atoms left at each time interval from both trial. Make a graph of your data showing the average number of atoms remaining versus time

...July 8, 2013
The HalfLife of a Radioisotope
By Jeremiah Stoddard
Abstract:
The half-life of a radioisotope is the time required for half the atoms in a given sample to undergo radioactive, or nuclear, decay. Half-life is given the symbol t1/2.Different radioisotopes have different half-lives. The amount of radioactive isotope remaining can be calculated using the equation,
ln [ (A)0 / (A) t1/2 ] = kt1/2 , or, rearranged: ln 2 = kt1/2. A sample data set was provided due to safety concerns. Using the data set, a half-life of 14.46 days was calculated using graphical linear regression analysis.
Introduction:
Unstable isotopes of certain elements spontaneously disintegrate. Their nuclei discharge particles or energy. Observing the decay stages using an appropriate instrument allows the researcher to determine the radioactive decay rate. The decay rate can be calculated using the formula: ln [ (A)0 / (A) t1/2 ] = kt.
The half-life of the isotope was considered to be the time at which the activity has dropped to ½ its original value and was given the symbol, t1/2. Calculation of the half-life was determined with the equation ln [ (A)0 / (A) t1/2 ] = kt1/2 , or, rearranged: ln 2 = kt1/2.
Materials:
This lab was performed under theoretical...

...
The Half-Life of a Radioisotope:
10-22-14
Abstract: The half-life of a radioisotope is the time required for half the atoms in a given sample to undergo radioactive, or nuclear decay. The amount of radioactive isotope remaining can be calculated using the equation, t1/2 = .693/K. A sample data set was provided due to safety concerns. Using the data set, a half-life of 14.27days -1
was calculated using graphical linear regression analysis.
Introduction:
The purpose of this experiment is to determine the half-life of an unknown radioisotope. Half-life is defined as the time it takes for one half of the atoms in in a radioactive sample to decay. Data will be collected on the activity of a radioactive isotope vs. elapsed time, the half-life will then be determined by two different types of graphical analysis.
Methods/Procedure:
Using the provided data in Table 1, the time in days, the normalized activity of the unknown (A’), and the natural log of the normalized activity of the unknown (ln A’) were calculated to determine beta emission half-life, and the half-life of the radioisotope. This data was then plotted on a graph to determine the half-life.
The calculation for A’ was A’unk = At...

...PHY101 - Lab 12
15/7/26 18:21
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Lab 12
Counting Atoms and
Nuclear Physics
Introduction: Connecting Your Learning
This laboratory activity will model the relationship between the rate of radioactive decay in a
sample and the amount of radioactive material that is capable of undergoing radioactive decay.
Many processes in nature behave this way. For example, the rateof change in the population
depends on the number of people present, and the same is true with radioactive decay. The rate of
change associated with the decay of one nucleon to another depends on the number of nucleons
present. This information can be used to determine the age of ancient artifacts, and applied to
modern nuclear medicine.
Resources and Assignments
Required
Assignments
Lab 14
Materials from
Lab Kit
None
Materials
(student
100 pennies
https://www.riolearn.org/content/phy/phy101/PHY101_INTER_0000_v5/LABS/lab12.shtml?encrypted-sectionid=Tko1Mm1kWVcxVTZMR0t4dlduN2x1UT09
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PHY101 - Lab 12
supplied)
15/7/26 18:21
Container to hold the pennies
Focusing Your Learning
Lesson Objectives
By the end of this lesson, you should be able to:
1. Discuss the process of nuclear decay in terms of radioactive half-life.
2. Use an Excel spreadsheet to organize experimental data that models nuclear decay.
3. Use the data collected to plot an Excel graph and use the...

...Title
To determine the half-life of beer foam
Purpose
In this experiment, we will make the bear foam as much as possible by pouring fast and using warm beer and try to estimate the half-life of beer foam based on the changing of height while the foam is collapsing.
Theory
A quantity is said to be subject to exponential decay if it decreases at a rate proportional to its value. Symbolically, this process can be expressed by the following differential equation, where N is the quantity and λ (lambda) is a positive number called the decay constant.
Figure 1
Figure 1
Exponential laws are common to many physical phenomena. Examples are the amplitude of an oscillator subject to linear friction, the discharge of a capacitor, cooling processes, or radioactive systems. In this experiment, we will make the beer foam as much as possible by pouring fast and using warm beer. The bubbles burst randomly so rather like the decay of radioactive nuclei, the rate of decay of beer bubbles is proportional to the number of bubbles as follows:
dNdt=-λN
In order to solve this differential equation, we could apply the following formula:
N=N0e-λt
Where
No is the original number of bubbles
N is the number of bubbles at time t
λ is the decay constant
Design
* Variables
* Independent variables are time, measured in seconds after the beer is pouring into the graduated cylinder.
* Dependent variable is the height of beer...

...Lab 7: Geologic Time
9
Answer Sheet
Name(s)
1. As an example of how radioactive decay works, the TA may lead a small demonstration. Each student will receive one penny and stand up. At this point all of the students are parent isotopes. Every student should then flip their penny. Students whose penny lands heads-up should sit down. These students who are now seated are now daughter isotopes. The remaining standing students should again flip their penny, and students whose penny lands heads-up should sit down to become daughter isotopes.
a. How many students started out standing?
All of them
b. How many daughter isotopes were produced after the first flip of the pennies?
About Half
c. How many parent isotopes remained after the second flip of the pennies?
About a quarter
d. How well does each flip (or half-life) actually eliminate half of the remaining parent isotopes?
Decently well
e. Would d.) be improved by making the sample population smaller or larger? Why?
D would be improved by making it larger because larger numbers represent more general populations. Likelihood of eliminating half would be greater.
2.) Sometimes numerical dates are referred to as ‘absolute dates’. Why do you suppose this is? Why might these numerical dates not actually be absolute dates?
Because it gives us a number but there is still a range on the amount of error....

...HalfLife Experiment
My hypothesis would be that after each shaking
about half of the remaining candies would be logo-up
and half of them logo-down. That's why the shaking
represents a "half-life".
half-life || total time (sec) || # of undecayed atoms || # of decayed atoms
0 0 100 0
1 5 65 35
2 10 51 28
3 15 23 14
4 20 11 12
5 25 8 3
6 30 5 3
According to my data no my hypothesis was not correct because the number of candies removed after each shaking
cannot be the same. It will always be approximately
half of what it was on the previous shaking, because
the starting number for each shaking will be only about
half of what it was the previous time.
HalfLife is the time taken for the radioactivity of a specified isotope to fall to half its original value.
When does a radioactive sample emit the largest number of...

...Lab Report
Atomic Dating Using Isotopes
Answer the following questions about the results of this activity. Record your answers in the boxes.
Send your completed lab report to your instructor. Don’t forget to save your lab report to your computer!
Reference: Isotope Half-Life Chart
Isotope
Product
HalfLife
Carbon-14
Nitrogen-14
5730 years
Potassium - 40
Argon - 40
1,280 million years
Rubidium - 87
Strontium -8 7
48,800 million years
Thorium - 232
Lead – 208
14,010 million years
Uranium - 235
Lead - 297
704 million years
Uranium - 238
Lead - 206
4,470 million years
Activity 1 – Calibration
Place your data from Activity 1 in the appropriate boxes below. Calculate the age of the calibration standards using the following information.
Fraction of sample remaining = remaining ppm of sample/initial ppm of sample
Age of sample = half-life value of isotope X number of half-lives elapsed
Calibration Standard
Initial ppm
Remaining ppm
Age of Standard
Low
Carbon-14
12000
5998
6000
High
Uranium-235
600000
151000
150000
1. Explain if the instrument appears to be calibrated based on the data you obtained for the Low Calibration Standard.
2. Explain if the instrument appears to be calibrated...