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
horrorfan [7]
3 years ago
12

An unknown radioactive substance has a half-life of 3.20 hours . If 16.5 g of the substance is currently present, what mass A0 w

as present 8.00 hours ago
Chemistry
1 answer:
guajiro [1.7K]3 years ago
6 0

Answer:

the amount present 8 hours ago is Ao = 93.338 g

Explanation:

the radioactive decay is given by

A = Ao * 2^(- t/T)

where T = half-life of the substance , t= time , A= amount of substance at time t , Ao= amount of substance at time 0

therefore at t=8 hours , A=16.5 gr

Ao = A*2^(t/T) = 16.5 g * 2^(8 hours/3.20 hours) = 93.338 g

Ao = 93.338 g

You might be interested in
What will be the amount of sugar in milligrams if the size of the milk chocolate bar is reduced from 11.630 g to 4.000 g ?
Dima020 [189]

The amount of sugar is 2621 mg

Why?

The complete question is:

A 12.630 g milk chocolate bar is found to contain 8.315 g of sugar.

Part B. What will be the amount of sugar in milligrams if the size of the milk chocolate bar is reduced from 12.630 g to 4.000 g ?

To find the answer we have to determine first the amount of sugar in milligrams per gram of chocolate bar. We can find that by applying the following conversion factor:

\frac{8.315 gSugar}{12.630 g Chocolate}*\frac{1000mg}{1g}=658.35mgSugar/gChocolate

Now, we have to determine the amount of sugar in milligrams if we had a chocolate bar with 4.000 g:

4.000gChocolate*\frac{658.35mgSugar}{1gChocolate}=2621mgSugar

Have a nice day!

5 0
3 years ago
Is the asthenosphere or the lithosphere closer to the outer core
Murrr4er [49]
The asthenosphere is directly below the lithosphere so the answer to your question is the asthenosphere, because the outer core is towards the center of Earth.
4 0
4 years ago
Explain the different between a molecule and a compound.
nevsk [136]

Answer:

-A molecule is the smallesr part is compound whereas a compound is the combination of two or more atoms in a fixed proportion by wiehgt.

- A glass of water is an example of compound but a small portion of water can be called molecule.

5 0
3 years ago
Zn + H2SO4 ZnSO4 + H2<br><br> The mole ratio of zinc to zinc sulfate is
ValentinkaMS [17]

Answer:

Ratio is 1:1

Explanation:

I do not see any coefficients infront of the reactants and the products, therefore, we can automatically assume that every reactant and product is 1 mole. Don't get confused by the 4 off the O. It just means that 1 mole of sulfate has 1 zinc and 4 oxygens.

6 0
3 years ago
Will vote brainliest and 5 star
svetoff [14.1K]

Answer:

it is B

Explanation:

hope it helps you

4 0
3 years ago
Other questions:
  • Help with questions
    9·1 answer
  • Calculate the number of kilojoules to warm 125 g of iron from 23.5 degrees C to 78 degrees C
    11·1 answer
  • Which element can expand its valence shell to accommodate more than eight electrons? which element can expand its valence shell
    14·2 answers
  • How can one determine if a bond between two atoms is ionic covalent or metallic?
    7·1 answer
  • Which equation represents the oxidation half-reaction for this redox reaction?
    9·1 answer
  • What is the product of the reaction of an alcohol and a carboxylic acid when heated together
    15·1 answer
  • Lithium and oxygen only exist in nature as Diatomic Molecules. True or False
    9·1 answer
  • I need an answer ASAP
    8·1 answer
  • Which phrase describes a feature of an earthquake’s epicenter?
    5·2 answers
  • A student wants to test how plants grow in different
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!