Answer Happy

Use the following information for questions 1 and 2. Beginning with 1.00 g of a sample of an unknown radioactive isotope, 0.05130 g of the isotope will remain after 225,000 years. Question 1 What is the half-life of the isotope? y Question 2 Again beginning with 1.00 g of this isotope, how much will remain after 100,000 years? 18 Type numbers in the boxes. 10 points Type numbers in the boxes. 10 points
Question 3 A laboratory investigation shows that a sample of uranium ore contains 5.37 mg of U and 2.52 mg of Pb. Calculate the age of the ore. The half-life of 2U is 4-5 × 109 yr. Type numbers in the boxes, 10 points
Use the following information for questions 4-6. The isotope 208 T1 undergoes ß decay with a half-life of 3.1 min. Question 4 What isotope is produced by the decay? A. O Hg-212 B. O Pb-212 C. O Pb-208 D. OHg-208 E. O Pb-210 F.OHg-210 Question 5 How long will it take for 99.0% of a sample of pure 208T1 to decay? min Select one 10 points Type numbe 10 points
Question 5 How long will it take for 99.0% of a sample of pure 208 T1 to decay? min Question 6 What percentage of a sample of pure 208T1 remains un-decayed after 25 min? 96