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
igomit [66]
3 years ago
11

Potassium-40 has a half-life of 1.3 billion years. as the potassium-40 isotope decays, it becomes argon. if a rock was formed wi

th 12 g of potassium-40, approximately how long would it take for 75% of the potassium-40 to be replaced by argon?
a. 1.3 billion years
b. 2.6 billion years
c. 5.2 billion years
d. 650 million years
Chemistry
2 answers:
Marina CMI [18]3 years ago
3 0
The half life of a substance is the time taken by a radioactive substance to decay by half its original mass. In this case, the half life of Potassium-40 is 1.3 billion years. 
Original mass of Potassium-40 = 12 g (100%)
New mass after the decay = 3 g ( 25 %, since 75% was replaced by argon)
New mass = Original mass × (1/2)^n ; where n is the number of half lives. 
 3 = 12 × (1/2)^n
(1/2)^n = 1/4 
      n = 2 
Therefore; the time taken will be 1.3 × 2 = 2.6 Billion years
Rom4ik [11]3 years ago
3 0

Answer:Potassium is a crucial element for the healthy operation of the human body. Potassium occurs naturally in our environment (and thus our bodies) as three isotopes: Potassium-39, Potassium-40, and Potassium-41. Their current abundances are 93.26%, 0.012% and 6.728%. A typical human body contains about 3.0 grams of Potassium per kilogram of body mass.

How much Potassium-40 is present in a person with a mass of 80 kg?

If, on average, the decay of Potassium-40 results in 1.10 MeV of energy absorbed, determine the effective dose (in Sieverts) per year due to Potassium-40 in an 80-kg body. Assume an RBE of 1.2. The half-life of Potassium-40 is 1.28 x 109 years.

Explanation:

You might be interested in
What is the net charge of a nitrogen atom with 8 electrons
DaniilM [7]

Answer:

– 1

Explanation:

From the question given above, we obtained the following:

Electron = 8

Net charge of nitrogen =.?

Nitrogen has atomic number of 7. This also means that nitrogen has 7 proton because atomic number of an element is the equal to number of protons in the atom of the element.

Thus, we can obtain the net charge of nitrogen with 8 electrons by calculating the difference between the protons and electrons of the nitrogen atom. This can be obtained as follow:

Proton = 7

Electron = 8

Net charge = Proton – Electron

Net charge = 7 – 8

Net charge = – 1

Therefore, the net charge of the nitrogen atom with 8 electrons is – 1

7 0
3 years ago
Suppose you need to prepare 141.9 mL of a 0.223 M aqueous solution of NaCl. What mass of NaCl do you need to use to make the sol
Afina-wow [57]

Answer:

1.811 g

Explanation:

The computation of the mass need to use to make the solution is shown below:

We know that molarity is

Molarity = \frac{Number\ of\ moles}{Volume\ in\ L}

So,

Number\ of\ moles = Molarity\ \times Volume\ in\ L

= 0.223\times 0.141

= 0.031 moles

Now

Mass = moles \times Molecualr\ weight

where,

The Molecular weight of NaCl is 58.44 g/mole

And, the moles are  0.031 moles

So, the mass of NaCL is

= 0.031 \times 58.44

= 1.811 g

We simply applied the above formulas

3 0
3 years ago
What 100 plus 124000
kodGreya [7K]
100 + 124000 = 124100
6 0
3 years ago
Read 2 more answers
How is the miscibility of two liquids related to their polarity?
makvit [3.9K]

Answer:

The more polar the liquid, the more likely that it is miscible with water. The polarity of a liquid does not affect its miscibility with water. The less polar the liquid, the more likely that it is miscible with water. The more polar the liquid, the less likely that it is miscible with water.

Explanation:

hope it helps you

4 0
2 years ago
How many grams of hydrogen gas would be produced from the use of 9.5 moles of aluminum
DIA [1.3K]

Answer:

Identify one disadvantage to each of the following models of electron configuration:

Dot structures

Arrow and line diagrams

Written electron configurations

Explanation:

Identify one disadvantage to each of the following models of electron configuration:

Dot structures

Arrow and line diagrams

Written electron configurations

8 0
3 years ago
Other questions:
  • Which lists the correct order of the steps?<br> 4,2,1,3<br>4,1,3,2<br> 4,3,1, 2<br>4, 2, 3.1​
    5·1 answer
  • Which best describes the process of igneous rock formation?
    13·1 answer
  • An acid containing the cooh group is called a carbo-oxy acid.
    14·1 answer
  • Write a balanced chemical equation for the reaction that occurs when calcium metal undergoes a combination reaction with O2(g)?
    14·1 answer
  • Derek needs a tool that delivers 25.00 mL of a sodium hydroxide solution. What tool would be best for him to use?
    9·1 answer
  • What the sample will look like after the temperature is increased from 300 K to 450 KK at constant pressure?
    6·1 answer
  • 9. Write the number in place value table of 820245<br>​
    10·1 answer
  • Which statement accurately describes binary star systems?
    10·2 answers
  • When a screen is used to easily separate substances, what physical properties are being used?
    12·1 answer
  • Which of the following is not part of our solar system?
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!