When an atom does decay, the process is random. In reality there is no way of knowing the instantaneous rate of decay at a particular moment of time. On the other hand, an average rate of decay can be found which is known as the half life. The half life of a substance is the average time taken for half the number of nuclei in a sample to decay. A substance with a long half life will decay slowly, while a substance with a short half life will decay rapidly. (Kirk)
Every element has its own decay constant ( which is used to find the number of given radioactive particles after a certain time period. The formula used to find the number of particles which are undergoing radioactive decay after a certain time is: where is the initial number of particles, is the decay constant, and t is the time elapsed. (Half-Life0
Data Collection
Data Processing
Calculations
Calculating Half Life
Average Half Life=time needed for # of molecules to half
Half Life 1-3800s
Half Life 2-3600s
Therefore average half life=
Calculating Decay Constant
LOBF
Therefore
Transformed Graph
Therefore, the slope represents which is the decay constant, and the intercept is the , which is the initial number of particles.
Works Cited
"Half-Life." ScienceWorld. Web. 29 Dec. 2009. <http://scienceworld.wolfram.com/physics/Half-Life.html>.
Kirk, Tim. Physics for the Ib Diploma. New York: Oxford Univ Pr (Sd), 2007. Print.
"Physics 30: Atomic Physics - Half-Life and Radioactive Decay." Saskatchewan Learning - Welcome to Saskatchewan Learning. Web. 28 Dec. 2009. <http://www.sasked.gov.sk.ca/docs/physics/u8b3phy.html>.