Astatine -211 has half a life of seven hours. If u start with 50.0 grams of astatine-211, how much will remain after 28 hours

Respuesta :

Answer:

3.125 grams

Explanation:

Applying,

R = ([tex]2^{t/n}[/tex])R'............... Equation 1

Where R = Original mass of Astatine-211, R' = mass of Astatine-211 left after decay, t = total disintegeration time, n = halflife of Astatine-211

make R' the subject of the equation

R' = R/([tex]2^{t/n}[/tex])............ Equation 2

From the question,

Given: R = 50 grams, t = 28 hours, n = 7 hours

Substitute into equation 2

R' = 50/([tex]2^{28/7}[/tex])

R' = 50/(2⁴)

R' = 50/16

R' = 3.125 grams