Answer:
equal to
Step-by-step explanation:
two negatives equals positive
Answer:
Sorry the screenshot is black but i would like to help if you can repost, it?
Step-by-step explanation:
About 92 days are taken for 90 % of the material to <em>decay</em>.
The mass of radioisotopes (), measured in milligrams, decreases exponentially in time (), measured in days. The model that represents such decrease is described below:
(1)
Where:
- - Initial mass, in milligrams.
- - Current mass, in milligrams.
- - Time constant, in days.
In addition, the time constant is defined in terms of half-life (), in days:
(2)
If we know that , and , then the time required for decaying is:
About 92 days are taken for 90 % of the material to <em>decay</em>.
We kindly invite to check this question on half-life: brainly.com/question/24710827
The expression would be $0.20 x f. Once you figure out what the 'f' variable stands for, you have to multiply it by $0.20, and you will have your answer.