1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
netineya [11]
3 years ago
10

A nuclear waste site. cesium-137 is a particularly dangerous by-product of nuclear reactors. it has a half-life of 30 years. it

can be readily absorbed into the food chain and is one of the materials that would be stored in the proposed waste site at yucca mountain (see the article opening this section). suppose we place 3000 grams of cesium-137 in a nuclear waste site.how much cesium-137 will be present after 60 years, or two half-lives?
Chemistry
1 answer:
hram777 [196]3 years ago
4 0
The mass decay rate is of the form
m(t) = m_{0} e^{-kt}
where
m₀ = 3000 g,the initial mass
k = the decay constant
t = time, years.

Because the half-life is 30 years, therefore
e^{-30k} =  \frac{1}{2} \\\ -30k = ln(0.5) \\ k =  \frac{ln(0.5)}{-30} =0.0231

After 60 years, the mass remaining is
m = 3000 e^{-0.0231*60} = 750 \, g

Answer: 750 g

You might be interested in
Which statement is incorrect?
Katena32 [7]

Answer:

e. When the indicator changes color and remains, 2 more drops of the solution in the buret should be added.

Explanation:

<em>Which statement is incorrect? </em>

<em>Select one: </em>

<em> a. The volume of solution in the buret should be recorded when the endpoint is reached. </em> CORRECT. At the endpoint, the titrant is expected to have completely reacted with the titrand.

<em>b. It is good practice to place the flask over a white background to better observe the color change of the solution.</em>  CORRECT. Using a white background makes it easier to detect the changes in the color of the indicator.

<em>c. The endpoint is when the indicator changes color.</em> CORRECT. This is the function of an indicator.

<em>d. Phenolphthalein will go from a colorless solution to a pink solution for the addition of NaOH to an acid solution.</em>  CORRECT. Phenolphthalein is colorless when pH < 8.3 and it is pink when pH > 10.0.

<em>e. When the indicator changes color and remains, 2 more drops of the solution in the buret should be added.</em> INCORRECT. When the endpoint is reached, no more titrant should be added.

4 0
3 years ago
Reflecting and refracting telescopes are used to gather radiation from space. Which of these statements best explains why a refr
galben [10]
I think the correct answer from the choices listed above is option A. A refracting telescope is made smaller than a reflecting telescope because small lenses cause less distortion in images than big lenses. <span> They are not subject to chromatic aberration because reflected light does not disperse according to wavelength.</span>
6 0
3 years ago
How much heat energy is required to raise the temperature of 0.368 kg of copper from 23.0 ∘C to 60.0 ∘C? The specific heat of co
Dmitriy789 [7]
23.0 + 60.0 = 83.0° C heat energy is required to raise
7 0
3 years ago
What is the correct sequence of events in the food chain?
Veseljchak [2.6K]
I believe it is the fourth choice because the producer would use sunlight to make food, then the next choice fhat has anything to do with the producer is [D]. if i’m wrong i’m sorry but I believe that would be the write anwser.
7 0
2 years ago
Which phrase best describes an exothermic chemical reaction? a does not absorb any energy b forms products with higher bond ener
-Dominant- [34]
<span>The correct answer is d. The reaction releases more energy than it absorbs. An example of an exothermic reaction is fire. Connecting the carbon atoms in wood with the oxygen in the air causes flames and gives of heat and light.</span>
8 0
3 years ago
Other questions:
  • Match the mixture with its description.
    9·2 answers
  • Give an example of homeostasis in your body
    13·1 answer
  • Who arranged the first periodic table.
    12·1 answer
  • Balance each of the following redox reactions occurring in basic solution
    12·1 answer
  • If you were going to build a system to check the effectiveness of automobile catalytic converters on cars, what substances would
    11·1 answer
  • HELP ME with THIS I am time i have a little bit of time and still have more questions !!! CHEMISTRY!!
    15·1 answer
  • How many moles are there in 3.612 x 1024 atoms of Sulfur?
    8·1 answer
  • Suppose three neutrons are released when an atom in a sample of fissionable nuclei undergoes fission. Each of these neutrons has
    10·1 answer
  • For each process, predict the sign on the entropy change and write a sentence or two to explain how to make this prediction with
    9·1 answer
  • The positvie part of the atom found in the center of the atom
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!