Question

the radioactive isotope europium decays with a first order rate constant of 0.062 year-1. What fraction of the europium in a sample is still present 55.0 years later

Answer 1

0.033

Step-by-step explanation:

From;

N/No = e^-kt

N/No = fraction of radioactive material left.

k= decay constant

t= time

N/No = e^-0.062 ×55

N/No = 0.033