Mantles for gas lanterns contain thorium, because it forms an oxide that can survive being heated to incandescence for long periods of time. Natural thorium is almost 100% 232Th , with a half-life of 1.405 × 1010 y. Randomized Variablesm = 270 mg If an average lantern mantle contains 270 mg of thorium, what is its activity in Bq?

A certain container has 0.56grams of 90Sr. Calculate the activity of this material in unitsof Curies. The half-life of 90Sr is 28.8 years.

A radioactive substance decays from 60mg to 12.6mg in 20 years according to the exponential decay model y=ae-bx, where a is the initial amount and y is the amount remaining after x years. a) find the b -value b) Use the exact b-value to write the exponential decay model for this substance with initial amount 60 mg, then use that model to find the half-life.

Hello please someone help me answer this problem set, thank you! Part A: A particular smoke detector contains 1.05 μCi of  241Am241Am, with a half-life of 458 years.  The isotope is encased in a thin aluminum container. Calculate the mass of 241 Am in grams in the detector. Express your answer numerically in grams.   Part B:  Fears of radiation exposure from normal use of such detectors are largely unfounded. Identify reasons why 241 Am smoke detectors are perfectly safe. Select all that apply a. The penetrating power of αα radiation is limited. b. Ions get trapped by electrodes. c. The amount of americium is very little. d. The number of αα particles leaving the case is low. e. The detector has a plastic cover.  f. The detector is housed in an aluminum case.