A radioactive sample contains two different types of radioactive nuclei: A, with half-life 5.0 days, and B, with half-life 30.0 days. Initially, the decay rate of the A-type nucleus is 64 times that of the B-type nucleus. When will their decay rates be equal

Answers

Answer 1

Answer:

t = 39.42 days

Explanation:

To do this, we need to use the general expression for decay rate:

R = R₀ exp(-λt)    (1)

According to the problem, decay rate of A initially is 64 times rate of B, so we can say the following:

A₀ = 64B₀   (2)

The value of λ can be determined using:

λ = ln2 / t(1/2)  (3)

Let's calculate first the value of λ for each nuclei:

For A: λ₁ = ln2 / 5 = 0.1286 day⁻¹

For B: λ₂ = ln2 / 30 = 0.0231 day⁻¹

Now, let's write an expression using (1) for each nuclei.

A = A₀ exp(-0.1286t)

A = 64B₀ exp(-0.1286t)   (3)

B = B₀ exp(-0.0231t)    (4)

We want to know the time when A = B , therefore, we can actually equals (3) and (4) and solve for t:

64B₀ exp(-0.1286t) = B₀ exp(-0.0231t)

64 exp(-0.1286t) = exp(-0.0231t)

ln(64 * exp(-0.1286t)) = ln(exp(-0.0231t))

ln64 + ln(exp(-0.1286t))= -0.0231t

4.1589 - 0.1286t = -0.0231t

4.1589 = (0.1286 - 0.0231)t

t = 4.1589 / 0.1055

t = 39.42 days

So, in 39 days, the decay rates of A and B will be the same.

Hope this helps


Related Questions

12. An electrolysis reaction is
A. hydrophobic.
B. spontaneous.
C. exothermic.
D. non-spontaneous.

Answers

Answer: D.) non-spontaneous.

Explanation:

For each of the following compounds, decide whether the compound's solubility in aqueous solution changes with pH. If the solubility does change, pick the pH at which you'd expect the highest solubility. You'll find Ksp data in the ALEKS Data tab. compound Does solubility change with pH

Answers

Answer: Hello attached below is the complete question and using data from ALEKS data tab

answer:

PbCl₂ :  Yes , PH = 3

CaC0₃ : Yes, PH = 3

AgCn : Yes , PH = 3 .

Explanation:

For PbCl₂  

PbCl₂ solubility will change ( decrease )  with increase in PH, and the PH at which PbCl₂ will be most soluble is at PH = 3

For CaC0₃

Addition of -ions which increases the PH level will cause a decrease in the solubility of  CaC0₃ hence the PH at which it will be most soluble in an aqueous solution is PH = 3

For AgCn

Increase in the PH level there would be a decrease in the solubility of AgCn hence the PH at which AgCn is most soluble ( highest solubility ) = 3

The ability of a solute to be able to dissolve is called solubility. Yes, at pH 3, the solubility of lead chloride, calcium carbonate, and silver cyanide.

What is solubility?

The ability of the solute to get dissolved in a solvent to form a saturated solution is called solubility.

For lead chloride, the solubility will decrease as the pH will increase and is most soluble at a pH of 3.

For calcium carbonate, the addition of ions increases the pH will result in a decreased solubility, and will be most soluble at pH 3.

For silver cyanide increased pH decreases the solubility and is most soluble at a pH of three.

Therefore, solubility decrease with an increase in pH due to the concentration factor.

Learn more about solubility here:

https://brainly.com/question/22985530

What is the molar mass of Ca(NO3)2?

Answers

Answer:

The molar mass is 40.1+2×(14+3(16))=40.1+2×(62)=164.1g/mol.

Which substance is the best oxidizing agent?

A. NaOH
B. H2O
C. Xe
D. HCI
E. O3

Answers

Answer:

the answer is A.

Explanation:

Elemental fluorine, for example, is the strongest common oxidizing agent.

Is it dangerous to remove gunpowder from firecracker​

Answers

Gun powder and any other firework explosive needs combustion to explode so if there’s no fire around the firecracker it’s 999999.99999999% likely you’ll be okay unless it gets in ur eyes or u snort it

How does the water cycle show precision in God's creation?
HELP ME!!

Answers

Explanation:

He used just the right amount of matter in water to get it to evaporate at a normal temperature and to condense into clouds for rain.

To cause water evaporate at a regular temperature and condense in clouds for rain, God has employed precisely the proper amount of substance in the water.

What is water cycle?

Water is constantly circulated throughout the Earth-atmosphere system throughout the water cycle, also known as the hydrologic cycle. The five key stages of the water cycle—evaporation, transpiration, condensate, precipitation, and runoff—are the most crucial. Water is used by all of the processes in the cycle, but its distribution changes over time even while the overall amount of water is largely constant.

Water is converted from its liquid state to its gaseous, or smoke, state through evaporation. This transfer happens when some water molecules have accumulated enough kinetic energy to launch themselves off the water's surface. To cause water evaporate at a regular temperature and condense in clouds for rain, God has employed precisely the proper amount of substance in the water.

Therefore, to cause water evaporate at a regular temperature and condense in clouds for rain, God has employed precisely the proper amount of substance in the water.

To know more about water cycle. here:

https://brainly.com/question/9243222

#SPJ2

By what factor does [OH- ] change when the pH increases by 1.7?

Answers

the values change in factors of ten.

For a reaction that has reactant A in its rate law, select which factor(s) affect the reaction rate of reactant A. Choose one or more: A. temperature B. change in concentration of a reactant C. catalyst D. change in concentration of a product E. physical state of the reactants

Answers

Answer:

Option B

Explanation:

The rate law is represented as

Rate of the reaction = [tex]k [A^x][B^y][/tex]

Here K is the rate constant

A is the concentration of substance A

B is the concentration of substance B

Hence, If  reactant A is in the rate law equation, then if its concentration varies then it will impact the rate of the reaction

Hence, option B is correct

Explain what matter is, and all of the states it can have.

Answers

Answer:

matter is anything that occupies space

states of matter : solid,liquid, gas,plasma

Answer:

matter can be anything, tables chairs, literally anything. it has volume and takes up space.

Explanation:

Solids, liquids, gases, plasmas, and Bose-Einstein condensates (BEC)

How many moles are in 3.87 x 10 ^24 molecules of carbon?

Answers

Answer:

1 mole contains 6.02⋅1023 particles

Explanation:

Explanation:

X×6.02⋅1023=3.75⋅1024→

X=3.75⋅10246.02⋅1023=0.623⋅101=6.23 moles

If the fan and power source are not connected to anything else, the amount of electrical energy is the same as the amount of mechanical energy. What is this rule known as?

1. transference of energy
2. conversion of energy
3. adaptation of energy
4. conservation of energy

Answers

Answer:

not B

Explanation:

my friend got it wrong

Why is a wire used to connect the electrodes in an electrochemical cell?
O A. To provide the metal that is the oxidizing agent
B. To prevent the flow of protons from electrodes
C. So ions can flow from one electrode to another
D. So electrons can flow from one electrode to another

Answers

Answer:

D. So electrons can flow from one electrode to another

Explanation:

An electrochemical cell is any cell in which electricity is produced by reason of a chemical change.

An electrochemical cell consists of two electrodes, these two electrodes are connected using a wire.

Usually, electrons flow from one electrode to another via this wire thereby enabling the electrochemical processes of oxidation and reduction in the cell to proceed effectively.

A student reads a barometer in the laboratory and finds the prevailing atmospheric pressure to be 736 mmHg. Express this pressure in torr and in atmospheres.

Answers

Answer:

736 mmHg = 0.97 atm (Approx.)

736 mmHg = 736 Torr

Explanation:

Given barometer in the laboratory atmospheric pressure data:

Atmospheric pressure in mmHg = 736 mmHg

Find:

Change given data into Torr

Change given data in atm (atmospheric pressure)

Computation:

We know that;

1 atm = 760 mmHg

So,

736 mmHg = 736 / 760

736 mmHg = 0.97 atm (Approx.)

We know that;

760 mmHg = 760 Torr

So,

736 mmHg = 736 Torr

Information normally shown as a continuous wave is analog or digital. Examples include music cds and smartphones is it analog or digital. Takes up a lot of space and degrades over time is it analog or digital. Examples include dimmer light switches and cameras that use film is it analog or digital. Purer data is more accurate and has more details is it analog or digital. Please help

Answers

Answer:

Music CDs and smartphones are digital.

Explanation:

Music CDs and smartphones are digital. Analogue takes up a lot of space and degrades with the [passage of time while on the other hand, digital takes less space and degrades in large piece of time. Dimmer light switches and cameras that use film is it analog not digital. The major difference between both signals is that the analog signals have continuous electronic signals, while digital signals have non-continuous electronic signals.

A 0.125 g sample of unknown hydrocarbon is prepared for combustion analysis. After the hydrocarbon undergoes complete combustion, 0.4225 g of CO2 and 0.0865 g of H2O are produced. What is the empirical formula of the unknown

Answers

Answer:

Empirical formula is CH

Explanation:

A hydrocarbon, CₐHₓ reacts with oxygen in the combustion reaction as follows:

CₐHₓ + O₂ → a CO₂ + x/2 H₂O

That means we can find the moles of C and H from the moles of CO2 and H2O. As empirical formula is defined as the simplest whole-number ratio of atoms in a molecule, we can determine it as follows:

Moles CO2 = Moles C -Molar mass: 44.01g/mol:

0.4225g * (1mol / 44.01g) = 0.0096 moles C

Moles H2O -Molar mass: 18.01g/mol:

0.0865g H2O * (1mol / 18.01g) = 0.0048moles H2O * (2mol H / 1mol H2O) =

0.0096 moles H

The ratio of atoms of C:H is:

0.0096moles C / 0.0096moles H = 1

That means empirical formula is CH

Which of the following would result in being able to dissolve a greater amount of gas in a solution? ​

Answers

Answer:

Lower the temperature of the solution

A simple way to look at kinetic energy is

A. Violent motion
B. The energy involved when you sit down
C. The energy when you move
D. The energy in a candy bar
E. The high energy, not known to be essential

Answers

Answer:

c I do believe good luck with the answer

C. The energy when you move

Hl Weakly dissociates in water according to the chemical equation below. H20+ Hl <-> H3O^+ + l- What is a conjugate acid-base pair in this reaction?

Answers

Answer:

https://www.clutchprep.com/chemistry/practice-problems/70217/hi-aq-h2o-l-h3o-aq-i-aq-identify-each-as-either-a-bronsted-lowry-acid-bronsted-l

Explanation:

https://www.clutchprep.com/chemistry/practice-problems/70217/hi-aq-h2o-l-h3o-aq-i-aq-identify-each-as-either-a-bronsted-lowry-acid-bronsted-l

in an expirement a scientist should

Answers

I suppose there are answer choices you forgot to list but in general

They should think of a question
They should form a hypothesis
Do research and test
Have an independent and dependent variable
Have repetitions and replications

If there’s answer choices put them in the comments and I’ll answer it

A sample of gas at 90 degrees Celsius occupies 15.5 L. This gas is heated to occupy a new volume of 20.3L. What is the new temperature of the gas?

Answers

Answer:

202 °C

Explanation:

From the question given above, the following data were obtained:

Initial temperature (T₁) = 90 °C

Initial volume (V₁) = 15.5 L

Final volume (V₂) = 20.3 L

Final temperature (T₂) =?

Next, we shall convert 90 °C to Kelvin temperature. This is illustrated below:

T(K) = T(°C) + 273

Initial temperature (T₁) = 90 °C

Initial temperature (T₁) = 90 °C + 273

Initial temperature (T₁) = 363 K

Next, we shall determine the final temperature.

Initial temperature (T₁) = 363 K

Initial volume (V₁) = 15.5 L

Final volume (V₂) = 20.3 L

Final temperature (T₂) =?

V₁ / T₁ = V₂ / T₂

15.5 / 363 = 20.3 / T₂

Cross multiply

15.5 × T₂ = 363 × 20.3

15.5 × T₂ = 7368.9

Divide both side by 15.5

T₂ = 7368.9 / 15.5

T₂ ≈ 475 K

Finally, we shall convert 475 K to celsius temperature. This is illustrated below:

T(°C) = T(K) – 273

T₂ = 475 – 273

T₂ = 202 °C

Thus, the new temperature of the gas is 202 °C

Use the equations below to calculate the enthalpy of formation for propane gas, C3H8, from its elements, hydrogen gas and solid carbon. Please hurry!!

Answers

Answer: I got -4542.9kg/mol

Explanation:

Using the enthalpy relation, the enthalpy of formation of propane gas in the given equation is 4542.9 kJ/mol

[tex] △H_{f} = Product [/tex]

Using the enthalpy value of [tex] CO_{2} [/tex] and[tex] H_{2}0[/tex] given :

Product = [tex] 3CO_{2} + 4H_{2}0[/tex]

Product = 3(-393.5) + 4(-285.8) = - 2323.70

Reactant = [tex] C_{3}H_{8} + 5H_{2}0[/tex]

Water, H20 has △H = 0

Reactant = [tex] C_{3}H_{8} + 0[/tex]

Enthalpy of formation = product - Reactant

2219.2 = -2323.70 - (propane + 0)

2219.2 = - 2323.70 - propane

Propane = - 2323.70 - 2219.2

[tex] C_{3}H_{8} = - 4542.9 [/tex]

Therefore, the entalphy of formation of propane gas is - 4542.9 kJ/mol.

Learn more :https://brainly.com/question/1261360

The heat of combustion per mole for acetylene, C2H2(g), is -1299.5 kJ/mol. Assuming that the combustion products are CO2(g) and H2O(l), and given that the enthalpy of formation is -393.5 kJ/mol for CO2(g) and -285.8 kJ/mol for H2O(l), find the enthalpy of formation of C2H2(g).

Answers

Answer: The heat of combustion per mole for acetylene is 227.7 kJ/mol.

Explanation:

The combustion equation of acetylene is as follows.

[tex]C_{2}H_{2} + \frac{5}{2}O_{2} \rightarrow 2CO_{2} + H_{2}O[/tex]

Formula to calculate enthalpy of formation for a reaction is as follows.

[tex]\Delta H^{o}_{rxn} = \sum \Delta H_{products} - \sum \Delta H_{reactants}\\\Delta H^{o}_{rxn} = [2\Delta H^{o}_{f}(CO_{2}) + \Delta H^{o}_{f} (H_{2}O)] - [\Delta H^{o}_{f}(C_{2}H_{2}) + \frac{5}{2} \Delta H^{o}_{f} O_{2}]\\-1299.5 = 2(-393.5) + (-285.8) - \Delta H^{o}_{f} (C_{2}H_{2})\\\Delta H^{o}_{f} (C_{2}H_{2}) = 227.7 kJ/mol[/tex]

Thus, we can conclude that heat of combustion per mole for acetylene is 227.7 kJ/mol.

200.0g of a 3.0% NaF solution, how much distilled water do we weigh out?

197g of distilled water
194g of distilled water
140g of distilled water
170g of distilled water

Answers

Answer:

194g of distilled water.

Explanation:

Hello there!

In this case, according to the given information for this problem, it turns out possible for us to use the given mass of the solution and the percent by mass of NaF to firstly calculate the grams of this solute as shown below:

[tex]\%m=\frac{m_{solute}}{m_{solution}} *100\%\\\\m_{solute}=\frac{\%m*m_{solution}}{100\%} \\\\m_{solute}=\frac{3.0\%*200.0g}{100\%} \\\\m_{solute}=6g[/tex]

And finally, since the mass of solution is calculated by adding mass of solute and mass of solvent we obtain the mass of water (solvent) as follows:

[tex]m_w=200g-6g=194g[/tex]

Therefore, the answer is 194g of distilled water

Regards!

1. Which individuals are most likely to die before reproducing, those with adaptive traits or
nonadaptive traits? Why? (Hint: You may use the newt population as an example in your
explanation.)

Answers

Nonadaptive traits .

What frequency corresponds to an absorption line at 460 nm?
A. 1.53 x 1014 Hz
B. 6.88 x 1014 Hz
C. 6.52 x 1014 Hz
D. 4.32 x 1014 Hz

Answers

Answer:

C. 6.52 x 10^14 Hz

Explanation:

hope this helps

What type of chemical reaction is represented by this balanced equation? S8(s)+802(g)-->8SO2(g)

Answers

Answer: I think it could be Decomposition

Explanation: I think is composition because decomposition starts by being together and ends up as two

What is the oxidation state of nitrogen in Nz?

Answers

Answer:

the oxidation state of nitrogen is +5

What are the missing coefficients for H3PO4 + HCl = PCl5 + H2o

Answers

Answer:

H3PO4 + 5 HCl → PCl5 + 4 H2O

Explanation:

The given equation is

H3PO4 + HCl = PCl5 + H2O

The above chemical equation has one P atom on both the sides, hence phosphorus is balanced

There are 5 Cl on the RHS but only one Cl on the LHS. On balancing the chlorine, we get -

H3PO4 + 5HCl = PCl5 + H2O

Now, there are 8 hydrogen atom on the LHS but only two on the RHS. On balancing the hydrogen on both the sides, the new equation become

H3PO4 + 5HCl = PCl5 + 4H2O

Let us check for oxygen

Oxygen on LHS = 4 and oxygen on RHS = 4

Thus, the balanced equation is H3PO4 + 5HCl = PCl5 + 4H2O

How many atoms are in 6.7 moles of iron?

Answers

Answer:

4.034x10^24 atoms

Explanation:

6.7 x 6.023x10^23 = 4.034x10^24 atoms

4.0348348050000003e+24

:|

Please don't give me a wedsite

Answers

Answer: B and D!
Please mark brainliest
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