1 Gigapascal: One gigapascal (GPa) is equal to exactly one billion pascals. A pascal (Pa) is the SI unit for pressure define as one newton per square meter. 1 GPa = 1,000,000,000 Pa.
Answer:
288 grams
Explanation:
The amount of any radiative substance left after some time is calculated by
amount left = 
where x is the initial amount of substance
n is the number of half lives
one half live is the time in which amount of substance reduce to half of its initial value.
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amount left = 4.5 grams
half life of iodine-125 = 60 days
total time in which substance reduced to 4.5 grams = 360 days
thus,
number of half life in 60 days = 360/60 = 6
thus, there are period of 6 half lives
in each half life the amount of substance reduces to its previous half
let the initial amount be x grams
using the formula
amount left = 

Thus, 288 grams was the initial amount of iodine-125
Answer:
Hb would be 78.4% saturated.
Explanation:
This problem can be solved by using simple unitary method.
At 100 mm Hg pressure of oxygen, Hb is saturated by 98%
So, at 1 mm Hg pressure of oxygen, Hb is saturated by
%
Hence, at 80 mm Hg pressure of oxygen, Hb is saturated by
% or 78.4%
Therefore, at 80 mm Hg pressure of oxygen in the lungs, Hb would be 78.4% saturated.