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:
Answer:
1. 
2. 13.5 + 
3. 
6. 
These four options are rational;
Step-by-step explanation:
1.
equals to 10 * 10 = 100 which is rational
2. 13.5 +
equals 13.5 + 9 = 22.5
3.
-- 3+27 = 30
6. 
Option 4 and 5 are irrational because they include
and
which are not a perfect square and their answers will be non recurring and non terminating decimal fraction.
Answer:
25
I hope i got it in time :)
Answer:

Step-by-step explanation:
<u><em>Given equation is</em></u>

Adding 42 to both sides

Completing squares

Adding (3)² => 9 and (3)² => 9 to both sides

Comparing it with
where Center = (h,k) and Radius = r
We get:
Center = (3,3)
Radius = 
Answer:
1.7 or 1 7/10
Step-by-step explanation: