The half-life of polonium-210 is 138.4 days.?

Science & Mathematics by Anonymous 2018-05-18 21:39:24

Social Science

3 answers

How many milligrams of polonium-210 remain after 553.6 days if you start with 8.3 mg of the isotope? Answer in units of mg

Anonymous

use this equation .. A(t) = A(o) * (1/2)^(time / half life) so that .. A(t) = 8.3mg * (1/2)^(553.6 days / 138.4 days) = 0.52mg
Anonymous

Let n be the number of half-lives. (1/2)ⁿ = 138.4/553.6 Mass of polonium remains = (8.3 mg) × (1/2)ⁿ = (8.3 mg) × (138.4/553.6) = 2.1 mg (to 2 sig. fig.)
Anonymous

553.6/138.4 = exactly 4, so you'll end up with 1/2 x 1/2 x 1/2 x 1/2 of the original amount; you'll end up with 0.52 mg.