An isotope of cesium-137 has a half-life of 30 years. If 5.5 grams of cesium-137 disintigrates over a period of 105 years, how many grams of cesium-137 would remain? Round your answer to the thousandths place.

0.484 g

Step-by-step explanation:

N/No = (1/2)^t/t1/2

No = mass of cesium-137 originally present

N= mass of cesium-137 at time t

t1/2= half life of cesium-137

t = time taken

N/5.5=(1/2)^105/30

N/5.5=(1/2)^3.5

N/5.5= 0.088

N = 5.5 *  0.088

N= 0.484 g

4.5 ft

Step-by-step explanation:

Let us assume the height of the taller brother be x

And, the height of the shorter brother be y

Now according to the question

x + y = 10.33

x - y = 0.833

Now solve these two equations

2x = 11.666

x = 5.833

y = 10.33 - 5.83

= 4.5 ft