Select the correct answer.

If two half-lives have passed since a scientist collected a 1.00-gram sample of U-235, how much U-235 is left now?

Respuesta :

There is 0.25 g of U-235, because when a half-life passes, you need to divide by 2. Since two half-lives have passed, you need to divide by 4.

Answer:

0.25 g of U-235 isotope will left .

Explanation:

Formula used :

[tex]N=\frac{N_o}{2^n}[/tex]

where,

N = amount of U-235 left after n-half lives = ?

[tex]N_o[/tex] = Initial amount of the U-235 = 1.00 g

n = number of half lives passed = 2

[tex]N=\frac{1.00 g}{2^{2}}=0.25 g[/tex]

0.25 g of U-235 isotope will left .