The 4th option is correct
6.665 grams of the 13 grams remain after 8 hours.
<h3>How much of a 13 gram sample of iron-52 would remain after 8 hours?</h3>
The decay equation for the 13 grams of iron-52 is:

Where N is the amount of iron-52, and t is the time in years.
Where we used the fact that the half-life is exactly 8.3 hours.
Now, the amount that is left is given by N(8h), so we just need to replace the variable t by by 8 hours, so we get:

So 6.665 grams of the 13 grams remain after 8 hours.
If you want to learn more about half-life:
brainly.com/question/11152793
#SPJ1
Answer:

Step-by-step explanation:
![\sqrt{5} \times \sqrt{10} \\ = \sqrt{5} \times \sqrt[]{5} \times \sqrt{2} \\ = 5\sqrt{2}](https://tex.z-dn.net/?f=%20%5Csqrt%7B5%7D%20%20%5Ctimes%20%20%5Csqrt%7B10%7D%20%20%5C%5C%20%20%3D%20%20%5Csqrt%7B5%7D%20%20%5Ctimes%20%20%5Csqrt%5B%5D%7B5%7D%20%20%5Ctimes%20%20%5Csqrt%7B2%7D%20%20%5C%5C%20%20%20%3D%205%5Csqrt%7B2%7D%20)
<h3>Hope it is helpful....</h3>
First one the answer is A; Alexander needs 70 ft
y= 1/2x +2
if x=0 y=2 (0,2)
if x=2 y = 1/2 *2 +2 =1+2 =3 (2,3)
you now have two points so you can plot the line