Please just answer part B: In the years immediately following the explosion at t
ID: 789841 • Letter: P
Question
Please just answer part B:
In the years immediately following the explosion at the Chernobyl nuclear power plant, the concentration of 90Sr in cow's milk in southern Europe was slightly elevated. Some samples contained as much as 1.25 Bq/L of 90Sr radioactivity. The half-life for the Beta decay of strontium-90 is 28.8 years. Write a balanced radiochemical equation describing the decay of 90Sr. Tip: Enter the element symbol and then place the cursor before the symbol. Click on the isotope button in the Tools menu to add the stacked superscript and subscript before the element symbol. Use the right arrow key to navigate between the superscript, subscript, and element symbol. Plus signs (+) can be typed from the keyboard. Reaction arrows can be found in the Tools menu of the answer module. How many atoms of 90Sr are in a 225.0 mL glass of milk with 1.25 Bq/L of 90Sr radioactivity?Explanation / Answer
Activity =lamda* N
lamda = ln2/ half life = 0.693 / 28.8 yrs = 7.63 *10^-10 per sec
Activity = 1.25 Bq per litre
for 225ml it is 0.225* 1.25 = 0.28125 Bq.
N = activity / Lamda = 0.28125/(7.63 *10^-10) = 3.6 * 10^ 8 atoms.