Question

9select the correct answer from each drop-down menu. The High Life of the radioactive element beryllium 13 is $5 \times {10}^{10}$seconds, and half life of the radioactive element beryllium 15 is $2 \times 10 {}^{7}$seconds. The half-life of _____ is ______ X greater than half life of _____.

Answer 1

In this problem, divide the half life of the radioactive element beryllium 15 by the half life of the radioactive element beryllium 13

so

$\frac{2\cdot10^{(-7)}}{5\cdot10^{(-10)}}=0.4\cdot10^3=400$

therefore

The half-life of radioactive element beryllium 15 is 400 times greater than half life of he radioactive element beryllium 13