Explanation:
1) Initial mass of the Cesium-137=
= 180 mg
Mass of Cesium after time t = N
Formula used :
Half life of the cesium-137 =
= initial mass of isotope
N = mass of the parent isotope left after the time, (t)
= half life of the isotope
= rate constant

Now put all the given values in this formula, we get
Mass that remains after t years.

Therefore, the parent isotope remain after one half life will be, 100 grams.
2)
t = 70 years


N = 35.73 mg
35.73 mg of cesium-137 will remain after 70 years.
3)


N = 1 mg
t = ?

t = 224.80 years ≈ 225 years
After 225 years only 1 mg of cesium-137 will remain.
Answer:
5.35m H2O2 x 34.02g/1m H2O2 = 182g H2O2
Explanation:
<span>17.5 g
35 ppt stands for 35 parts per thousand. So let's convert that to a decimal number by taking 35 and dividing by 1000.
35/1000 = 0.035
Now multiply that number by the number of grams of seawater you have. So
0.035 * 500 g = 17.5 g
So you have 17.5 grams of salt when you have 500 grams of seawater.</span>