A-10B-1
C-4
D-7
E-3
F-6
G-2
H-5
I-9
J-8
Answer:
A. 0.78 g
Step-by-step explanation:
The <em>half-life</em> of F-20 (11 s) is the time it takes for half of it to decay.
After one half-life, half (50 %) of the original amount will remain.
After a second half-life, half of that amount (25 %) will remain, and so on.
We can construct a table as follows:
No. of Fraction Mass
<u>half-lives</u> <u>t/s</u> <u>Remaining</u> <u>Remaining/g
</u>
0 0 1 25
1 11 ½ 12.5
2 22 ¼ 6.2
3 33 ⅛ 3.1
4 44 ¹/₁₆ 1.6
5 55 ¹/₃₂ 0.78
6 66 ¹/₆₄ 0.39
We see that 0.78 g of F-20 remain after five half-lives (55 s).
The answer is 7.85
First, you divide the diameter by two to get the radius (2.5) and then you multiply by pi(3.14) to get 7.85
Answer:
three
Step-by-step explanation:
1) solving for roots
2) Quadratic formula
3) By completing square