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:Change values to whole numbers.
Convert any mixed numbers to fractions.
Convert 3 1/8
3 1/8 = 25/8
We now have:
5 : 3 1/8 = 5 : 25/8
Convert the whole number 5 to a fraction with 1 in the denominator.
We then have:
5 : 3 1/8 = 5/1 : 25/8
Convert fractions to integers by eliminating the denominators.
Our two fractions have unlike denominators so we find the Least Common Denominator and rewrite our fractions as necessary with the common denominator
LCD(5/1, 25/8) = 8
We now have:
5 : 3 1/8 = 40/8 : 25/8
Our two fractions now have like denominators so we can multiply both by 8 to eliminate the denominators.
We then have:
5 : 3 1/8 = 40 : 25
Try to reduce the ratio further with the greatest common factor (GCF).
The GCF of 40 and 25 is 5
Divide both terms by the GCF, 5:
40 ÷ 5 = 8
25 ÷ 5 = 5
The ratio 40 : 25 can be reduced to lowest terms by dividing both terms by the GCF = 5 :
40 : 25 = 8 : 5
Therefore:
5 : 3 1/8 = 8 : 5
Step-by-step explanation:
What you do is divide the sum by 2. You will come out with and answer of 1891. Now, to figure out the years they were invented you take the difference of 192 and divide that in half also. It will come out to 96. Now, you subtract 1891 by 96 and that is the year the pencil was invented (1795=pencil) now with the other half (1891) you add on 96 and you’ll come out with the answer of 1987.
Pencil=1795
Laptop computer=1987.
Hope this helped!
Area
=3*2/2+6*1/2+3*6/2+(6+7)*6/2
=54
Answer:
E = 50
D = 150
Step-by-step explanation:
We know that the exterior angle is equal to the sum of the opposite interior angles
D + E = 200
D = 3E
Substituting that into the equation
3E + E = 200
Combing terms
4E = 200
Divide by 4
4E /4 = 200/4
E = 50
D = 3E
D = 3*50 = 150
