Question

a radioactive substance has a decay rate of 0.073 per minute. how many grams of a 120 - gram sample will remain radioactive after 30 minutes? round the answer to the nearest tenth of a gram, and do not include the unit in your answer. note: the formula for radioactive substance is $w = me^{-kt}$ provide your answer below:

Explanation:

Step1: Identify the values

$M = 120$, $k=0.073$, $t = 30$

Step2: Substitute values into formula

$W=120\times e^{-0.073\times30}$

Step3: Calculate exponent

$-0.073\times30=-2.19$

Step4: Calculate $e^{-2.19}$

$e^{-2.19}\approx0.1119$

Step5: Calculate $W$

$W = 120\times0.1119 = 13.428\approx13.4$

Answer:

$13.4$