Question

1. In this activity, we will be exploring the relationship between the amount of a radioactive substance and the rate of decay. There are many forms of radioactive decay. For this activity we will be using beta (B) decay, when a neutron decays into an electron and proton, and gamma (7) decay, when an atom emits energy through a gamma photon. B- Decay y Decay Unstable High Energy+ Atom Neutron Low Energy+ Cesium-137 decays into an unstable Barium-137 atom through beta (8) decay. In the following videos, we collected a sample of the unstable Barium-137 and measured the energy emitted (y) as it goes from the excited state to a stable state. The image below demonstrates the process: B- Decay Cs 137 Ba 137 (Excited State) Bq137 (Stable) When a gamma (7) ray hits the detector in a geiger counter, it produces a count. Our Geiger Counter outputs both the total counts and the number of counts registered every 13 seconds.

I need help with 1, 2, and 3.

Answer 1

J. The only requerement to solve for half life is that At is One half of Ao .. If we set Ao=1 then A= 1 / 2 = 0.5

2. Using the values of Ao and At we have kt 1 1 2 - Jekt » ekt = 1/2 1 → logekt - log 1/2 -> kt = log2 log!/2 -) t = k - t-ts/2 ln (0.5) k

No Let us try to calculate tsiz from the given data At t= 51s the count is 1544 counts/13 At t- 1985. the count gets halved i. l. 774 (approx) counts / 13. t 312 1985-515 -] 475

::/61 ) en (0.5) ln (0.5) t 3/2 ln (0.5) 147 -j. s 0.0045-1