Question

scandium47 has a half-life of 35s. suppose you have a 45g sample of scadium 47 how much of the sample remains unchanged after 140 seconds

Answer 1

Via the half-life equation we have:

`A_(final)=A_(initial)((1)/(2))^{(t)/(h) }`

Where A is the amount initially and final amount after some time has passed, t is the time elapsed, h is the half life time and so:

`A_(final)=45((1)/(2))^(140)/(35)  = 2.8125g`

Therefore there will be 2.8125 grams left after 140 seconds.