Answer:
Explanation:
The formula for this, the easy one, is
where No is the initial amount of the element, t is the time in years, and H is the half life. Filling in:
and simplifying a bit:
and
N = 48.0(.0625) so
N = 3 mg left after 12.3 years
To solve this problem it is necessary to use the concepts related to Snell's law.
Snell's law establishes that reflection is subject to

Where,
Angle between the normal surface at the point of contact
n = Indices of refraction for corresponding media
The total internal reflection would then be given by





Therefore the
would be equal to



Therefore the largest value of the angle α is 30.27°
It's when each of the seven BIOMES occur