Question

There's a 50 gram sample of our Ra-229 it is half-life is 4 minutes how much will be left after 12 minutes

Answer 1

6.25 grams of Ra-229

To find this, set up a chart. Start the first row with the original mass and the time of zero as half lives haven't started.

For the next row, halve the amount and set the time to four. Continue this process until twelve minutes as you halve the last amount given.

Hope this helps!