The mass of cesium left afer 120 years if the original mass of cesium is 8640 with an half-life of 30 years, is 540 grams.
<h3>What is half-life?</h3>
This can be defined as the time taken for half the amount of a radioactive substance to decay.
To calculate the amount of cesium left after 120 years, we use the formua below.
Formula:
- R' = R/(
)............. Equation 1
Where:
- R = Original amount of Cesium
- R' = New amount of cesium
- T = Total time
- t = Half-life
From the question,
Given:
- R = 8640
- T = 120 years
- t = 30 years
Substitute these values into equation 1
- R' = 8640/(
) - R' = 8640/

- R' = 8640/16
- R' = 540 grams.
Hence, The mass of cesium left afer 120 years is 540 grams.
Learn more about half-life here: brainly.com/question/25750315
I know I'm definitely wrong: 540. it looks like a right angle.
I did on the calculator:
18 * 90 = 1620
1620 / 3 = 540
Answer: 275$
I'm not entirely sure I did this right! But at least try!!!
Step-by-step explanation:
20/100 = 55/x (cross multiply)
20x = 5,500 (divide)
X = 275
Solution :
1). The cost of the formula is given as :
$ 19,350 + $12 x
2). 95%
for the prediction is :


(rounding off)
3). r = 0.92
Therefore, 
That is 84.64 % of the variability in the moving cost is best explained by the number of moves.