Question

**PLEASE HELP!!**
A radioactive isotope has a half life of 4 days. The amount remaining undecayed from 1 kg of the isotope after 20 days is..?

Answer 1

P.S. Answer is 31 grams... I'm just confused on how to get that

Answer 2

(1)(.5)^20/4

Answer 3

That'll give you .03125 kg. Then just make it into grams. 31.25.

Answer 4

Hope that helps.

Answer 5

final=initial(.5)^time/half life time

Answer 6

^for future reference

Answer 7

Yay, thank you :) @JoyLin

Answer 8

No problem! Anytime! Feel free to message me if any questions are left unanswered here. I'll do my best to help.