Answer:
I think B 82.3%
Step-by-step explanation:
Answer:
The amount of Polonium-210 left in his body after 72 days is 6.937 μg.
Step-by-step explanation:
The decay rate of Polonium-210 is the following:
(1)
Where:
N(t) is the quantity of Po-210 at time t =?
N₀ is the initial quantity of Po-210 = 10 μg
λ is the decay constant
t is the time = 72 d
The decay rate is 0.502%, hence the quantity that still remains in Alexander is 99.498%.
First, we need to find the decay constant:
(2)
Where t(1/2) is the half-life of Po-210 = 138.376 days
By entering equation (2) into (1) we have:
Therefore, the amount of Polonium-210 left in his body after 72 days is 6.937 μg.
I hope it helps you!
First you have to remember that to find a percentage you can multiply a number by the percentage's decimal form, for example 40% of 100 would be .40 * 100.
Anyways, 24*.40 =9.6.
To find the percentage however, you must divide 24/40 which equals 0.6, which is equal to the percentage 60%.
To find the third question, you must multiply 24 by 2.5 (0.4 * 2.5 = 1) and you should get 60.
The last question you may have made a typo on, you repeated the first question.
Answer: red is 13.36
Blue is 93.625
Step-by-step explanation:
Let the red marbles be y
Based on the question,red is 4times which means 4y
And blue is 7times greater than red which means 7(4y)
Blue + red=107
7(4y) + 4y=107
28y+4y=107
32y=107
Divide both sides by 32
Y=3.34
Red =4y
Red= 4(3.34)
Red =13.36
Blue= 7(4y)
Blue=7(4×3.34)
Blue= 93.625