Iodine-131 half life 8.040 how long will it take for a 40 gram sample of iodine-131 to decay to 0.75 grams

Answers

Answer 1

Answer:

See explanation below

Explanation:

To get this, we need to apply the general expression for half life decay:

N = N₀e(-λt)    (1)

Where:

N and N₀ would be the final and innitial quantities, in this case, masses.

t: time required to decay

λ: factor related to half life

From the above expression we need λ and t. To get λ we use the following expression:

λ = t₁₂/ln2   (2)

And we have the value of half life, so, replacing we have:

λ = 8.04 / ln2 = 11.6

Now, we can replace in (1) and then, solve for t:

0.75 = 40 exp(-11.6t)

0.75 / 40 = exp(-11.6t)

ln(0.01875) = -11.6t

-3.9766 = -11.6t

t = -3.9766 / -11.6

t = 0.34 days

Related Questions

5. How would you calculate the pH (NOT POH) of a base when given

the concentration of [OHJ?

Answers

Answer:

pOH = -log₁₀ [OH-]

pH = 14 - pOH

Explanation:

First of all, calculate the value of pOH from  the hydroxide concentration do this using the equation below;

pOH = -log₁₀ [OH-]

After obtaining the pOH, calculate pH using the equation below:

pH + pOH = 14

pH = 14 - pOH

How many protons, neutrons, and electrons are found in a neutral atom of hydrogen-333?

Answers

Answer:

Explanation:

A hydrogen atom has an atomic number of 1.

So it's proton number will always be 1.

A neutral hydrogen atom does not have any charge.

So it has the same amount of electrons as protons, which turns out to be also 1.

A neutral hydrogen atom has an atomic mass of ≈

1.00794 amu ≈ 1 amu.

To find the amount of neutrons, we take the proton number and subtract it from the mass number.

1 − 1 = 0

So a neutral hydrogen atom has no neutrons.

In summary,

A hydrogen atom has

1 proton

1 electron

0 neutrons

I hope that helps!

which process is a chemical change​

Answers

Burning a match, In chemistry, there are two basic types of change, these are physical and chemical change. In physical change, no new material is formed and the process is reversible while in chemical change new materials are formed and the process is irreversible

Titaium oxside is often added to food to color it white. If a jelly bean contains approximately 1.28x10-5 moles of TiO2, how many grams of TiO2 are in a jelly bean

Answers

Answer:

1.02 × 10⁻³ g

Explanation:

Step 1: Given data

Number of moles of titanium (IV) oxide in 1 jelly bean (n): 1.28 × 10⁻⁵ moles

Step 2: Calculate the mass (in grams) corresponding to 1.28 × 10⁻⁵ moles of TiO₂

To convert moles to mass, we need a conversion factor. In this case, it is the molar mass of TiO₂: 79.87 g/mol.

1.28 × 10⁻⁵ mol TiO₂ × 79.87 g TiO₂/1 mol TiO₂ = 1.02 × 10⁻³ g TiO₂

Describe the three-dimensional property of an electromagnetic wave. Use the diagram below

Answers

Answer: The are waves that consist of vibrating electric and magnetic fields. They transmit energy through matter or across space. Some electromagnetic waves are generally harmless. Like other waves, electromagnetic waves have properties of speed, wavelength, and frequency.

Explanation:

Give examples of how land resources are used in a city setting

Answers

Answer:

Land resources such as gravel and bedrock are used to construct buildings, roads, and sidewalks. Land is also where city structures—such as buildings, roads, and sidewalks—are constructed. People use land resources such as bedrock and aggregate to construct buildings, roads, and sidewalks.

I hope this answer helps

What mass of potassium would need 2350 J of energy in order to raise its temperature from 44.3°C to 57.8°C? (cpotassium = 0.753 J/g°C)

Answers

Answer:

Explanation:

q = mCΔT

m =CΔT/q

ΔT = 57.8°C - 44.3°C = 13.5°C

m = (0.753*13.5)/2350

m = 0.00433 g

The mass of potassium that will need 2350 J of energy in order to raise its temperature from 44.3°C to 57.8°C is 231.17 g

Data obtained from the question Heat (Q) = 2350 JInitial temperature (T₁) = 44.3 °CFinal temperature of water (T₂) = 57.8 °CChange in temperature (ΔT) = 57.8 – 44.3 = 13.5 °C Specific heat capacity (C) = 0.753 J/gºC Mass (M) =?

Q = MCΔT

2350 = M × 0.753 × 13.5

2350 = M × 10.1655

Divide both side by 10.1655

M = 2350 / 10.1655

M = 231.17 g

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4. At what temperature will 5.00 g of Cl, exert a pressure of 900. torr at a volume of 750 ml?​

Answers

Answer:

p=27.8atm

Explanation:

P = 27.8atm

At what temperature will 5.00 g of Cl2 exert a pressure of 900. mmHg at a volume of 750.

What change would shift the equilibrium system to the left?
A(g) + B(s) + Energy = 309) (3 points)
Adding more of gas C to the system
Heating the system
Increasing the volume
Removing some of gas C from the system

Answers

Answer:

C

Explanation:

sorry if its wrong but i think its right

Heating the system will shift the equilibrium system to the left.

The correct option is B.

What is equilibrium?

Chemical equilibrium is a state where no net change in the amounts of reactants and the products occurs during a reversible chemical reaction.

A reversible chemical reaction happens when the products react with the original reactants as soon as they are generated.

On a treadmill, you are walking continuously but not going anywhere, which can be said as equilibrium.

Thus, the correct option is B.

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How many moles is 8.3 x 10^12 atoms or particles of Br2
urgent

Answers

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

[tex]n = \frac{N}{L} \\[/tex]

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

We have

[tex]n = \frac{8.3 \times {10}^{12} }{6.02 \times {10}^{23} } \\ \\ \\ \\ \: \: \: \: \: \: \: = 1.379 \times {10}^{ - 11} \: \: \: \: moles[/tex]

Hope this helps you

On the bottom beam of the triple beam balance, each small division stands for
A.) one centimeter
B.) one milliliter
C.) one gram
D.) one-tenth of a gram

Answers

Answer:

Hello There!!

Explanation:

I believe the answer is D.) one-tenth of a gram.

hope this helps,have a great day!!

~Pinky~

[tex]\huge{\textbf{\textsf{{\color{navy}{An}}{\purple{sw}}{\pink{er}} {\color{pink}{:}}}}}[/tex]

D.) one-tenth of a gram

Thanks.Hope it helps.

At STP, which of the following would have the same number of molecules at 1 L of C2H4 gas? Assume that each behaves as an ideal gas.
A. 0.5 L of H2 gas
B. 2 L of H2O gas
C. 1 L of Ne gas
D. 3 L of Cl2 gas

Answers

Answer: 1L of Ne gas

The answer is Option C , 1L of Ne gas will have the same number of molecules at 1 L of C₂H₄ gas

What is STP ?

At standard temperature and pressure, a system is said to have a temperature of zero degrees centigrade (273 Kelvins) and the pressure equal to the atmosphere is always 1 atm.

Additionally, one mole of any gas at STP occupies a volume of 22.414 L.

This concept only holds true for gases.

So for a gas having same pressure , temperature and moles according to the Ideal Gas Law , volume also needs to be same

                                       

                                           pV=nRT

and in the given option ,Option C has the same volume as that of 1 L of C₂H₄ gas .

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Help meeeeee

A 280.0 sample of neon gas exerts a pressure of 660.0 mm Hg at 26.0°C. Assuming that the pressure remains constant, at what temperature in would the volume change to 440.0 ml?

Answers

Answer:

469.9K

Explanation:

Using Charles's law equation:

V1/T1 = V2/T2

Where;

V1 = initial volume (ml)

V2 = final volume (ml)

T1 = initial temperature (K)

T2 = final temperature (K)

Based on the information provided:

V1 = 280.0ml

V2 = 440.0 ml

T1 = 26.0°C = 26 + 273 = 299K

T2 = ?

Using V1/T1 = V2/T2

280/299 = 440/T2

0.936 = 440/T2

T2 = 440 ÷ 0.936

T2 = 469.9K

1) Escribe oraciones coherentes que incluyan los siguientes términos con los conceptos correspondientes:

CARBÓN-PETRÓLEO-GAS NATURAL-RECURSO NO RENOVABLE-

COMBUSTIBLES FÓSILES-HIDROCARBUROS-RESERVAS-CONTAMINACIÓN-

MAREAS NEGRAS

Answers

La respuesta correcta para esta pregunta abierta es la siguiente.

Estas son las oraciones apropiadas.

El carbón, el petróleo, y el gas natural son recursos naturales no renovables.

Estos generadores naturales de energía son considerados combustibles  fósiles que produce la mayor parte de hidrocarburos que se usan en el mundo. Sin embargo, estas reservas energéticas se están agotando porque son recursos naturales no renovables. Además, estos combustibles son altos generadores de contaminación como es el caso de las mareas negras.

Independientemente de estas ideas, es apropiado decir que los combustibles fósiles han sido fuertemente cuestionados por los ambientalistas y los científicos porque son causantes del llamado calentamiento global y del cambio climático.

Por esa razón, la sociedad y los expertos ambientalistas están pidiendo que los gobiernos comiencen a utilizar más energías alternativas y renovables como la energía solar y las turbinas de viento o energía eólica.

Consider the reaction.

2HF(g) +

H2(g) + F2(g)

At equilibrium at 600 K, the concentrations are as follows.

[HF] = 5.82 x 10-2 M

[H2] = 8.4 x 10-3M

[F2] = 8.4 x 10-3M

What is the value of Kea for the reaction expressed in scientific notation?

O 2.1 x 10-2

102.1 x 102

1.2 x 103

0 1.2 x 10-3

Answers

Answer:

0.021

Explanation:

Step 1: Write the balanced equation

2 HF(g) ⇄ H₂(g) + F₂(g)

Step 2: Calculate the value of the concentration equilibrium constant

The concentration equilibrium constant (K) is equal to the product of the concentrations of the products raised to their stoichiometric coefficients divided by the product of the concentrations of the reactants raised to their stoichiometric coefficients.

K for this reaction is:

K = [H₂] × [F₂] / [HF]²

K = (8.4 × 10⁻³) × (8.4 × 10⁻³) / (5.82 × 10⁻²)² = 0.021

Describe and show an example of valence electrons. What is a common trend you can remember to help you understand valence electrons?

Answers

Explanation:

valency from right to left in a Periodic Table in same period first increases then decreases and from top to bottom it is same for a same group

Concerning the disposal of materials at the end of the experiment, which methods are safe? Check all that apply.


[ANSWERS]


B. Dispose of pH paper in the trash.


C. Dump the cabbage indicator solution down the drain.


D. Ask your teacher to neutralize the acids and bases before disposal.

Answers

Answer:

B. Dispose of pH paper in the trash.

C. Dump the cabbage indicator solution down the drain.

D. Ask your teacher to neutralize the acids and bases before disposal.

Explanation:

Safe disposal of waste means disposal of waste in such a way that it does not pose a threat to the environment.

When pH paper is properly disposed in the trash, it does not constitute any risk to the environment.

When a cabbage indicator solution is disposed down the drain it does not contaminate the environment. It moves directly into the sewers and is properly disposed.

When acids and bases are properly neutralized before disposal, they don't lead to acid or base contamination of the environment.

How many joules of heat are needed to raise the temperature of 62.0 g of ethylene glycol from 13.1 C to 40.5C?

Answers

Answer:

Q = 4133.2 J

Explanation:

Hello there!

In this case, since these calorimetry problems are based off the following heat equation involving heat (Q), mass (m), specific heat (C) and temperatures (T):

[tex]Q=mC(T_2-T_1)[/tex]

Thus, we plug in the given variables to obtain:

[tex]Q=62.0 g*2.433 \frac{J}{g\°C}* (40.5\°C-13.1\°C)\\\\Q=4133.2J[/tex]

Regards!

How many moles of O₂ are needed to react completely with 35.0 mol of FeCl₃?


4FeCl3+3O2->2Fe2O3+3Cl2


The 2 for the second half of the equation is not a coefficient it’s supposed to be for 2Fe2 Not 2O3.

26.3 mol

46.7 mol

23.3 mol

10.0 mol

Answers

Answer:

26.3 mol O₂

Explanation:

Step 1: Write the balanced equation

4 FeCl₃ + 3 O₂ ⇒ 2 Fe₂O₃ + 6 Cl₂

Step 2: Establish the appropriate molar ratio

According to the balanced equation, the molar ratio of FeCl₃ to O₂ is 4:3.

Step 3: Calculate how many moles of O₂ are needed to react completely with 35.0 mol of FeCl₃

We will use the previously established molar ratio.

35.0 mol FeCl₃ × 3 mol O₂/4 mol FeCl₃ = 26.3 mol O₂

1. If you have 8.1 g CO₂ and 2.3 g H₂, which one is the limiting reactant. Show your work. 2. Calculate the theoretical yield of CH₄.

Answers

Answer:

2.95 g of CH₄

Explanation:

To start this, we determine the equation:

4H₂  + CO₂ →  CH₄  +  2H₂O

4 moles of hydrogen react to 1 mol of carbon dioxide in order to produce 1 mol of methane and 2 moles of water.

To determine the limiting reactant, we need to know the moles of each reactant.

8.1 g . 1 mol/ 44g = 0.184 moles of carbon dioxide

2.3 g . 1mol / 2g = 1.15 moles of hydrogen

4 moles of hydrogen react to 1 mol of CO₂

Then, 1.15 moles may react to (1.15 . 1) /4 = 0.2875 moles

We only have 0.184 moles of CO₂, so this is the limiting reactant. Not enough CO₂ to complete the 0.2875 moles that are needed.

Ratio is 1:1. 1 mol of CO₂ produces 1 mol of methane

Then, 0.184 moles of CO₂ will produce 0.184 moles of CH₄

We convert moles to mass: 0.184 mol . 16 g /mol = 2.95 g

Identify two ways that temperature plays a role in chemical changes.

Answers

Answer:

Increasing the temperature will cause chemical changes to occur faster. Decreasing the temperature, causes the particles to lose energy which causes them to move around less and slower. The less they move, the less collisions occur, and the less reactions occur between the chemicals = slower reaction rate.

Explanation:

Which of the following is an example of a molecular element?

a.NaCl b. CO2 c. Na d. O2

Answers

Answer:

oxygen (O2) is a molecular element

Explanation:

Molecular compound are chemical compounds that take the form of discrete molecules.

atomic element is an element which occurs independently as atoms and can react with other elements to form a compound

Ionic compounds are the compound which on dissolution form ions in solution

Mixture is the composition of different compounds

what is electromagnetic?​

Answers

Electromagnetism is a branch of physics that involves the study of the electromagnetic force. It is a type of interaction that occurs between electrically charged particles.

Answer:

relating to the interrelation of electric currents or fields and magnetic fields.

2 Iron(III) oxide (Fe2O3) is reduced by carbon on heating to give iron metal (Fe) and
carbon dioxide (CO2). (Ar values Fe 56, C 12,0 16)
When 480 g of Fe2O3 is heated with carbon, 336 g of Fe and 198 g of CO2 are produced.
Use the Law of Conservation of Mass to work out the mass of carbon that
reacted.
a

no links please i need this ASAP​

Answers

Using the law of conservation of mass, the mass of carbon reacted is 54 g of carbon.

What is the law of conservation of mass?

According to the law of conservation of mass, matter is neither created nor destroyed. This means that the total mass of reactants is equal to the total mass of products.

Total mass of the products = 336g + 198g = 534 g

Total mass of reactants = 480 g + x g

From the law of conservation of mass;  534 g = 480 g + x g

x g = 534 g - 480 g

x g = 54 g

Hence, 54 g of carbon reacted.

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Balloon has a volume of 600-ml at temperature of 360 K. If the temperature of
the balloon drops to 250 K, find the volume

Answers

Answer:

V₂ ≈416.7 mL

Explanation:

This question asks us to find the volume, given another volume and 2 temperatures in Kelvin. Based on this information, we must be using Charles's Law and the formula. Remember, his law states the volume of a gas is proportional to the temperature.

V₁ / T₁ = V₂ / T₂

where V₁ and V₂ are the first and second volumes, and T₁ and T₂ are the first and second temperature.

The balloon has a volume of 600 milliliters and a temperature of 360 K, but the temperature then drops to 250 K. So,

V₁= 600 mL T₁= 360 K T₂= 250 K

Substitute the values into the formula.

600 mL /360 K = V₂ / 250 K

Since we are solving for the second volume when the temperature is 250 K, we have to isolate the variable V₂. It is being divided by 250 K. The inverse o division is multiplication, so we multiply both sides by 250 K.

250 K * 600 mL /360 K = V₂ / 250 K * 250 K 250 K * 600 mL/360 K = V₂

The units of Kelvin cancel, so we are left with the units of mL.

250 * 600 mL/360=V₂416.666666667 mL= V₂

Let's round to the nearest tenth. The 6 in the hundredth place tells us to round to 6 to a 7.

416.7 mL ≈V₂

The volume of the balloon at 250 K is approximately 416.7 milliliters.

What is a jet stream. in your own words but be more detailed about what you say.
(don't send a link)

Answers

a narrow variable band of very strong predominantly westerly air currents encircling the globe several miles above the earth. There are typically two or three jet streams in each of the northern and southern hemispheres.

Name the process by which oxygen moves from alveoli to blood

Answers

diffusion...........the blood through the capillaries lining the alveolar walls. Once in the bloodstream, oxygen gets picked up by the hemoglobin in red blood cells.

A balloon contains 25.0 L of helium gas at 177 kPa. What is the volume when the balloon rises to an altitude where the pressure is only 43.0 kPa ? Assume the temperature remains constant.

A.34.2 L
B.68.8 L
C.46.5 L
D.103 L

Answers

I think answer is D not sure

147.0 g piece of metal was heated to 155 C and added to a calorimeter containing 75.0 grams of water. The temperature of the water in the calorimeter was 23.5 C. After the metal was added, the temperature rose to 33.5 C. What is the specific heat of the metal?

Answers

65.9 is the heat of the metal

Hot water is poured into four cups made of different materials (foam, glass, metal, plastic).After one minute, which will feel the warmest when you touch the OUTSIDE of the cup?

Answers

The answer to this is metal

Answer:

Metal

Explanation:

Foam, glass, and plastic don't absorb as much heat as metal does.

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At the beginning of the current year, Max Corp. granted restricted stock units (RSUs) representing 30 million of its $1 par common shares to executives, subject to forfeiture if employment is terminated within four years. After the recipients of the RSUs satisfy the vesting requirement, the company will distribute the shares. The common shares had a market price of $12 per share on the grant date. Ignoring taxes, what is the effect on earnings(net income) in the current year after the shares are granted to executives 1. How did mankind survive in the beginning? ChoicesA. 240 mmB. 120 mmC. 90 mmD. 40 mmPlease help ASAP and no freaking linksss!! What is the unit rate of 28 miles in 4 hours? 13. Each edge of a cube is the same length. What is the surface area of the 1cube represented by the net shown? help me only answer if you know no links or ill report youwhat is .5-6.7+1000 the formal operational stage around age 17 Which of the following best describes the impact of colonization and resulting African independence movementsin the second half of the 20th century?O Nations such as Ghana, which declared its independence from Britain in a bloody war, typified the colonialindependence movements of the 1960s.o Western interference disappeared with the independence of colonies like the Democratic Republic of Congo,where the rise of anti-communist dictators brought relative stability.O Nations such as Egypt eschewed movements such as the Non-Aligned Movement and Pan-Africanism, favoringinstead close colonial ties with Europe.O Nations such as South Africa and Ethiopia stepped into the power vacuum left by the departure of Westerncolonial powers and annexed neighboring territories. Find the length of side x in simplest radical form with a rational denominator.45X456 help plssssssssssssssssss E-dev de yorum nasl silinir? Why do scientists need an accurate atomic model? (2 points) The atom is the most important structure in the universe. The atom is the most important structure in the universe. It allows scientists to predict things about objects that are too small to see. It allows scientists to predict things about objects that are too small to see. Models allow scientists to avoid having to do real experiments. Models allow scientists to avoid having to do real experiments. The atom cannot be divided into smaller particles. Task 1:Listen to the Excerpt from Title of the Music Below and describe their musical elements witheach other.1. Nocturne Op. 9 No. 2 By Frederic Chopin.2. Symphony No. 6 "The Pathetique"movement No. 4 By Pytor Ilyich Tchaikovsky.3. "The Erlking" by Franz Schubert The tone of an argumentative research paper should be _____.Formal,Informal, or a bit of both? Write a paragraph comparing the Patriots and the Loyalists. If you were to have taken sides with one of them, which one would you have been and why?If anyone can help me with this thank you! (I will report any non-answers though.) Simplify 5 (x + 2) + 2 (x - 5) Mathematics 10x10x10 Order these numbers from least to greatest: 5, 0, 1, -13 -1-1 Convert 3/7 into a percent Based on what you know from the article and your own background knowledge, how does the Communist Party in China operate differently than political parties in the U.S.?