After 15 minutes, 30 g of a sample of polonium-218 remain unchanged. If the original sample had a mass of 960 g, what is the hal
f-life of polonium-218? Suppose you want to separate the leaves, acorns, and twigs from a pile of soil. Filtration and distillation are two processes of separating mixtures. Explain which process you would use and why.
Let's first calculate the remaining amount in percent: If 960g is 100 percent (starting amount), 30 g is how many percents: 960 g : 100% = 30 g : x x = 30 g * 100% / 960 g = 3.125% = 0.03125
Now, using the formula to calculate the number of half-lives: (1/2)ⁿ = x, where x is the remaining amount: x = 0.03125 n is the number of half-lives 1/2 stands for half-life.
The number of half-lives is 5. Now, <span>the number of half-lives (n) is a quotient of total time elapsed (T) and length of half-life (L): n = T/L We know: n = 5 T = 15 min L = ?
Thus L = T/n L = 15 min/5 = 3 minutes
Q2. Filtration should be chosen. Filtration and distillation are used to separate mixtures - filtration for the separation of heterogeneous mixtures and </span>distillation for the separation of homogeneous mixtures. Imagine that your pile of soil is a mixture. It consists of different components (the leaves, acorns, twigs), so it is the heterogeneous mixture. Therefore, to separate the leaves, acorns, twigs you will use filtration.