Question

How much of a radioactive kind of niobium will be left after 105 days if you start with 3,920 grams and the half-life is 35 days?

Answer 1

"490 grams" would be the correct solution.

Explanation:

The given values are:

Half time,

T = 35 days

Total time,

t = 105 days

As we know,

⇒
`A=A_o((1)/(2) )^{(t)/(T) }`

On substituting the values, we get

⇒
`=3920* ((1)/(2))^{(105)/(35) }`

⇒
`=3920* (0.5)^3`

⇒
`=3920* 0.125`

⇒
`=490 \ grams`