Radon gas ²²²₈₆Rn is a serious environmental hazard(see §20). It is a decay product of ²³⁸₉₂U, which is a relatively common constituent of rock. ²²²₈₆Rn undergoesα-decay to ²¹⁸₈₄Po. When ²²²₈₆Rn is created in the foundation of a house, it diffuses out into the basement airspace. If its lifetime were very short, it would decay before getting out of the rock. If it were very long, it would diffuse away into the atmosphere. Its half-life is 3.8 days, however, just right for causing a great deal of human radiation exposure. Given this half-life, use Gamow’s formula (17.30) to estimate the Q-value for this decay and compare with the measured value. Comment on the accuracy of your estimate.