Answer:
- <u>59.0891 g (rounded to 4 decimal places)</u>
Explanation:
<em>Half-life time</em> of a radioactive substance is the time for half of the substance to decay.
Thus, the amount of the radioactive substance that remains after a number n of half-lives is given by:
Where:
- A is the amount that remains of the substance after n half-lives have elapses, and
- A₀ is the starting amount of the substance.
In this problem, you have that the half-live for your sample (polonium-210) is 138 days and the number of days elapsed is 330 days. Thus, the number of half-lives elapsed is:
- 330 days / 138 days = 2.3913
Therefore, the amount of polonium-210 that will be left in 330 days is:
Hello! :)
Let's use PEMDAS.
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction
(5-2) = 3 Do parenthesis.
7 × 3 = 21 Multiply with what we got after doing the parenthesis.
9 + 21 = 30 Add with what we had left.
30
Hope this helps!
ELITEDIPER
Answer:
Number A. is True. B. is False. C. is IDK D. is False. E. is true.
Step-by-step explanation:
If you read it you can tell plus I broke it down and solved it on paper.
Area = length * width
Area = (n yds + 40 yds) * 30 yds
or
Area = (30 yds * n yards) + (30 yds * 40 yards)
This is if you add the area of the rides to the area of the arcade (the first parenthesis is the rides, the second is the arcade.)
For this case we have that by definition, the perimeter of the rectangle is given by:
Where:
W: Is the width of the rectangle
L: is the length of the rectangle
According to the data we have:
Substituting:
So, the width of the rectangle is 9 inches
So, the length of the rectangle is 15 inches
Answer:
the width of the rectangle is 9 inches
the length of the rectangle is 15 inches
