Question

Please help ill medal and fan!

After 15 minutes, 30 g of a sample of polonium-218 remain uncharged. If the original sample had a mass of 960 g, what is the half-life of polonium-218?

And

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.

Answer 1

Solutions for your questions are the following:
1. remaining amount is equal to:960 g : 100% = 30 g : xx = 30 g * 100% / 960 g
= 3.125%
= 0.03125
Now, we use this formula to calculate the number of half-lives:(1/2)ⁿ = x,
so,(1/2)ⁿ = 0.03125
to calculate n, use this equation:
n*log(1/2) = log(0.03125) n = log(0.03125)/log(1/2)
= log(0.03125)/log(0.5)
= -1.505/-0.301
n=5

Ifn = 5T = 15 min

Then
L = T/nL = 15 min/5
= 3 minutes

2. You should pick filtration. It is use to separate heterogeneous mixtures just like in the problem stated.