Question

PD-99 has a half-life of 22.3 hours. How many grams of a 89.8 gram sample would have decayed after exactly three half-lives?

A. 22.90 grams
B. 1.34 grams
C. 11.23 grams
D. 22.3 grams

Answer 1

11.23 grams

Step-by-step explanation:

Answer via Educere/ Founder's Education

Answer 2

Answer: The correct answer is Option C.

Step-by-step explanation:

To calculate the amount of sample left for the given half lives, we use the equation:

`a=(a_o)/(2^n)`

where,

a = amount of sample decayed = ?

`a_o` = initial amount of the sample = 89.8 g

n = number of half lives = 3

Putting values in above equation, we get:

`a=(89.8g)/(2^3)\\\\a=11.225g`

Amount of sample decayed after three half lives is 11.23 g

Hence, the correct answer is Option C.