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
The shape at the top is a trapezoid with width 2 cm and lengths 4 and 8 cm.
Its area is
4+8
-------- 2 cm = 12 cm^2
2
The lower part consists of two congruent triangles. The area of a triangle is
A = (1/2)(b)(h). Here, A = (1/2) (4)(5.75) = 11.5, so the area of both triangles is 23 cm^2.
Thus, the total area is (12+23) cm^2, or 35 cm^2.
Answer:
I cant see the question
Step-by-step explanation:
Answer:
x = -11
Step-by-step explanation:
First, get rid of parentheses:
5 + x - 2 = -8
Then, simplify:
3 + x = -8
Finally, subtract 3 on both sides:
x = -11
Hope this helps ^^