contestada


The half-life of a radioactive kind of thallium is 3 minutes. If you start with 80 grams of it,
how much will be left after 9 minutes?

Respuesta :

- After 3 minutes you have half. 40grams
- After 3 more minutes you have half of that. 20 grams
- After the last 3 minutes you have half of that. 10 grams