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
(2/3x + 2 - 1/6x + 4) • 1/5 ÷ 1/5
(1/2x + 6) • 1
1/2x + 6
Answer:

General Formulas and Concepts:
<u>Pre-Algebra I</u>
- Order of Operations: BPEMDAS
<u>Algebra I</u>
- Midpoint Formula:

Step-by-step explanation:
<u>Step 1: Define</u>
R (9, 3)
S (-1, -9)
<u>Step 2: Find midpoint</u>
- Substitute:

- Subtract:

- Divide:

Answer:The absolute value of a number is its distance away from zero. That number will always be positive, as you cannot be negative two feet away from something. So any absolute value equation set equal to a negative number is no solution, regardless of what that number is.
Step-by-step explanation:
there u go