Question

Use the following information to answer the next question While studying a radioactive phosphorous 34 p, it was discovered that a 128 g sample had decayed to 4.48 g after 60 seconds. The following table provides data corresponding to the decay. Mass (g) 128.0 4.48 73.0 41.9 23.9 7.80 Time (S) 60 0 50 10 20 1. Complete the following: Provide a graph of the data provided Determine the half-life of the radioactive phosphorous using the graph or other appropriate method. Explain how this answer was determined. 13.7 40 30 .

Answer 1

Let's graph mass vs time mass(8) 128 T(s) 0 73 41.9 23.9 13.7 7.8 50 4.48 60 10 20 30 40 mass vs time 140 120 100 80 60 y = 127.9e-0.056x 40 20 0 0 10 20 30 40 50 60 70 Remember that: 0.693t m = moe Comparing this with the equation: y = 127.9e- -0.056x Then: 0.693 = 0.056 ti 2 The half-life: ti = 12.375 s 2