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3 years ago

The half-life of Iodine-131 is approximately 8 days. Find the amount of Iodine-131 left from a 42 gram sample after 16 days.

Mathematics

1 answer:

AlexFokin [52]3 years ago

6 0

Answer:

Step-by-step explanation:

The formula for this is

$N=N_0(.5)^{\frac{t}{H}$ where

N is the amount of the element left after a certain amount of time (for us it is measured in days),

N₀ is the initial amount of the element in grams,

t is the number of days gone by, and

H is the half life of the element. Filling in:

$N=42(.5)^{\frac{16}{8}$ which simplifies a bit to

$N=42(.5)^2$ and a bit more to

N = 42(.25) which gives us a remaining amount of

N = 10.5

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maw [93]

Answer:

here is my answer is took me alot of time

Step-by-step explanation:

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3 years ago

5/4 cups is equal to

Arlecino [84]

5/4 cup is equal to one whole cup and 1/4 left over or 1 1/4

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3 years ago

Read 2 more answers

PLEASE HELP ME! I will mark you as BRAINLIEST if you answer this correctly.

horsena [70]

Answer:

0.92

Step-by-step explanation:

Each year, the value declines. This eliminates choices A and D.

The decline from 33000 to 30360 is slightly less than 10%, so the multiplier from one year to the next is slightly more than 1 -10% = 90%. The only choice in range is ...

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4 years ago

Factor 10c-25, please :)

Citrus2011 [14]

10c - 25

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3 years ago

Read 2 more answers

Yeah another one ha ha

boyakko [2]

Answer:

16.75 cubic inches

Step-by-step explanation:

<u>Key skills needed: Volume of a cylinder, Volume of a sphere</u>

1) To get the answer to this problem, you need to understand two formulas: The volume of a sphere, and The volume of a cylinder.

Volume of a sphere --> $V= \frac{4}{3}\pi r^3$ (V = volume, and r = radius)
Volume of a cylinder --> $V = \pi r^2h$ (V = volume, r = radius,h = height)

These formulas will be needed.

2) In order to solve this problem, we need to find the volumes of both, and the subtract them from one another to find the difference.

3) Let's start by finding the volumes:

Cylinder --> $V = \pi r^2h$

We have the radius (which is 2) and the height (which is 4)

This means we can solve --> $V = \pi(2^2)(4)$

2 squared is 4, so then it would be --> $V = \pi (4)(4)$
4 times 4 is 16 so $V = 16\pi$ ---> 16 pi is the same as 50.24 cubic inches (if you use 3.14 as pi).
Next is the Sphere--> $V = \frac{4}{3}\pi r^3$

We have the radius (which is 2) so we can solve

$V = \frac{4}{3}\pi (2^3)$
2 cubed is 8, so it would be --> $V = \frac{4}{3}\pi (8)$
8 times 4/3 is 32/3 so --> $V = \frac{32}{3}\pi$ --> which is Around 33.51 cubic inches

4) Now we have to find the difference, so we do:

50.24 - 33.51 = 16.74

This means your answer would be 16.75 as that is the closest one.

<em>Hope you understood and have a nice day!! :D</em>

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3 years ago