Question

Po-218 is an alpha emitter with a half-life of 3.0 minutes. If a sample contains 56 mg of Po-218, how many alpha emissions would occur in 6.0 minutes?


I got 2.4e20 but it said it was wrong. I did what my teacher showed us to do.

My work:


86(i got this by diving 100/2/2 then subtracting that from 100) X 1g/1000/mg X 6.022e23amu/1g X 1 atom/218 amu X 1 alpha particle/1 atom


what am i doing wrong?

Answer 1

http://www.jiskha.com/display.cgi?id=1286326760

Use your numbers, not those in DrBob's example.

Answer 2

thanks.

um..wait i think i get everything except how do you calculate the molar mass?

Answer 3

Doesn't Po-218 tell you the molar mass is 218?