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
Answer:
There is no correct answer
Step-by-step explanation:
4x+20
2x+6
4x+20=2x+6
4x–2x=6–20
2x=–14
x=–7
Answer:
C is the answer
Step-by-step explanation:
35+1=36
35-------------36
Answer:
Usual, because the result is between the minimum and maximum usual values.
Step-by-step explanation:
To identify if the value is usual or unusual we're going to use the Range rule of thumbs which states that most values should lie within 2 standard deviations of the mean. If the value lies outside those limits, we can tell that it's an unusual value.
Therefore:
Maximum usual value: μ + 2σ
Minimum usual value: μ - 2σ
In this case:
μ = 153.1
σ = 18.2
Therefore:
Maximum usual value: 189.5
Minimum usual value: 116.7
Therefore, the value of 187 lies within the limits. Therefore, the correct option is D. Usual, because the result is between the minimum and maximum usual values.
20% of 48.25
(20/100) * 48.25
(1/5) * 48.25
9.65
tip is 9.65