An element with a mass of 990 grams decays by 16.9% per minute. To the nearest minute, how long will it be until there are 80 grams of the element remaining?

Question

asked Dec 25, 2021 167k views

2 Answers

Zuu · Answer 1 · 2021-12-31T04:29:11+0000

Answer:

It will take 13.58 minutes until there are 80 grams of the element remaining

Explanation:

An element with a mass of 990 grams decays by 16.9% per minute.

We are supposed to find how long will it be until there are 80 grams of the element remaining

Formula :
N(t)=N_0(1-r)^t

N(t)=Amount after t minutes

N_0 =Initial amount

r = rate of decrease = 0.169

t = time in minutes

Substitute the values in the formula :

80=990(1-0.169)^t

(80)/(990)=0.831^t

t=13.58

Hence It will take 13.58 minutes until there are 80 grams of the element remaining