<span>The correct answer is b. Radon. Oxygen, Hyrdrogen, and Boron, are not radioactivel ike Radon and it regenerates quickly meaning that even though it has a short half-life period, it stays for a long time once released. It also has no taste so it's difficult to notice without proper gear because you can't feel it.</span>
Answer:
A is the answer; 'more-efficient extraction techniques
Explanation:
I just took the test and got it right :D
Answer:
15m
Explanation:
vi = 0
vf = 10
a = -9.8
10^2 = 0 + 2(-9.8)(x2-x1) = -5.1
20-5.1 = 14.9m = 15m
