4. Use the atomic model to answer the following questions

A. How many protons?

B. How many neutrons?

C. What is the name of this atom?​

The time taken for 0.240 mole sample of radiuim to decay to 1.88×10¯³ mole is 79.8 days

We'll begin by calculating the number of half-lives that has elapsed.

Original amount (N₀) = 0.240 mole

Amount remaining (N) = 1.88×10¯³ mole

N = 1/2ⁿ × N₀

1.88×10¯³ = 1/2ⁿ × 0.240

Cross multiply

1.88×10¯³ × 2ⁿ = 0.240

Divide both side by 1.88×10¯³

2ⁿ = 0.240 / 1.88×10¯³

2ⁿ = 128

2ⁿ = 2⁷

Thus, 7 half-lives has elapsed

Number of half-lives (n) = 7

Half-life (t½) = 11.4 days

t = n × t½

t = 7 × 11.4

Therefore, the time taken for 0.240 mole sample of radiuim to decay to 1.88×10¯³ mole is 79.8 days

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The partial pressure of oxygen is equal to 10.2 atm.

Given the following data:

To determine the partial pressure of oxygen:

First of all, we would find the total number of moles of the elements:

[tex]n=3.25+2.75[/tex]

n = 6 moles

Next, we would determine the mole fraction of the oxygen by using this formula:

[tex]Molefraction \;of \;a \;substance =\frac{No.\; of \; moles \;of \;substance}{Total \;no. \;of \; moles \;of \;substances}[/tex]

Substituting the values, we have:

[tex]Molefraction \;of \;a \;substance =\frac{2.75}{6} \\\\Molefraction \;of \;a \;substance =0.4583[/tex]

For oxygen:

[tex]Partial \;pressure = Molefraction \times Total\;pressure\\\\Partial \;pressure = 0.4583 \times 22.4[/tex]

Partial pressure of oxygen = 10.2 atm.

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Answer:

12.1

Explanation:

3.25 + 2.75= 6 moles total

then take: 3.25/6 to get 0.542

multiply 0.542 by 22.4 to get 12.1

the other answer solved for nitrogen, not oxygen.

Electrolysis is the production of a chemical reaction by passing an electric current to liquid containing ions.

Answer:

la primera va con la última

Answer:

32

Explanation:

Answer:

75% Cl-35 and 25% Cl-37

Explanation:

chlorine has two isotopes chlorine-35 and chlorine-37 with average atomic mass 35.5.find the percentage abundance of each isotopes​

assume Cl-35 has Y%  Then Cl-37 has (100-Y) %

The weighted average of 35.5 is given by

[(35 x Y) + ((100-Y) x 37)]/100 = 35.5

so

(35 x Y) + ((100-Y) x 37) =3550

35Y + 3700 -37Y =  3550

-2Y = -15075% Cl-35 and 25% Cl-37

Y = so average weight chlorine is

75% Cl-35 and 25% Cl-37

Fire extinguishment is referred to the stage in which flames are not visible

and the combustible item no longer generates heat.

This stage refers to when the fire has been put out through a fire

extinguisher or other compounds.   When fire is put out, there is no longer

flames present.

The absence of flames also means that there is no heat generation or

combustion products due to the absence of a heat source.

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ok done. Thank to me :>

Answer: Mass percent of Li: total mass Li = 6.94 g/mol. % Li = mass Li mass LiClO 2 × 100 % Li = 6 . ...

Mass percent of Cl: total mass Cl = 35.45 g/mol. % Cl = mass Cl mass LiClO 2 × 100 % Cl = 35 . ...

Mass percent of O: total mass O = 32.00 g/mol.

Explanation:

Answer:

5.39 X 10-4

Explanation:

Try Checking It Out If It Right Or Not

an ionic compound is made of two or more elements held by a strong electrostatic force. metal atoms lose electrons to become positive ions, and non metals gain electrons to become negative ions. ionic bonding occurs between metals and non metals

Answer:

Model C has more double the oxygen than A. I think it is B

Explanation:

Answer:

I believe they deserve to be here.

Explanation:

This is the answer i hope it helps

A sample of gas has Pi = 0.768 ATM, Vi = 10.5 L, and Ti = 300 K. What is the final pressure if VF = 7.85 L and T and f = 250 K?

The mass of the carbon dioxide that will be produced when 144 g of carbon react with 384 g of oxygen gas is 528 g

We'll begin by calculating the masses of C and O₂ that reacted and the mass of CO₂ produced from the balanced equation.

C + O₂ —> CO₂

Molar mass of C = 12 g/mol

Mass of C from the balanced equation = 1 × 12 = 12 g

Molar mass of O₂ = 2 × 16 = 32 g/mol

Mass of O₂ from the balanced equation = 1 × 32 = 32 g

Molar mass of CO₂ = 12 + (2×16) = 44 g/mol

Mass of CO₂ from the balanced equation = 1 ×44 = 44 g

SUMMARY:

From the balanced equation above,

12 g of C reacted with 32 g of O₂ to produce 44 g of CO₂

From the balanced equation above,

, 12 g of C reacted with 32 g of O₂.

Therefore,

144 g of C will react with = (144 × 32)/12 = 384 g of O₂.

From the calculations made above, we can see that both C and O₂ are sufficient for the reaction. Thus, C and O₂ are both limiting reactants.

From the balanced equation above,

balanced equation above, 12 g of C reacted to produce 44 g of CO₂.

Therefore,

144 g of C will react to produce = (144 × 44)/12 = 528 g of CO₂.

Thus, the mass of CO₂ obtained from the reaction is 528 g

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Answer:

933.33 m/ min

Explanation:

1 mile = 1.6 km

So the car travels 1.6× 35 km in 1 hour

One hour has 60 minutes

So speed of car = 1.6×35 km / 60 minutes

1km = 1000 m

Speed = 1.6×35×1000 m/ 60 minutes

= 933.33 meters per minute

A car is traveling 35 miles per hour. The speed that is measured in meters per minute is 933.33 m/ min.

Speed is the dimension of distance. It is calculated in meters per second. It is the rate of change of an object in a direction. Speed is calculated by dividing the distance by time. It is a scalar quantity.

Given, that a car is traveling 35 miles per hour. The speed is given, in miles we just have to convert the miles into meters per minute. Miles if the English unit of measurement and meter is the SI unit of measurement.

1 mile = 1.6 km

So the car travels 1.6× 35 km in 1 hour

One hour has 60 minutes

So speed of car = 1.6×35 km / 60 minutes

1km = 1000 m

Speed = 1.6 × 35 × 1000 m/ 60 minutes

= 933.33 meters per minute

Thus, the speed of the car is 933.33 m/ min.

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Answer:

Ideal Gas Law Calculator. Easily calculate the pressure, volume, temperature or quantity in moles of a gas using this combined gas law calculator (Boyle's law calculator, Charles's law calculator, Avogadro's law calculator and Gay Lussac's law calculator in one).Supports a variety of input metrics such as Celsius, Fahrenheit, Kelvin, Pascals, bars, atmospheres, and volume in both metric and

Answer: the answer is 0.074Hz

Explanation:

Given, (In air)

Velocity V=340m/s

Frequency f=20,000Hz

Wavelegth λ=?

V=f.λ

λ=

F

V

​

=

20,000

340

​

=0.017Hz

Also, Given (in Water)

Velocity, V=1480m/s

Frequencyf=20,000Hz

wavelength, λ=?

V=F.λ

λ=

F

V

​

=

20,000

1480

=​0.074Hz

Answer:

frequency

Explanation:

frequency is velocity/ wavelength

340/1.36

250

A cylindrical weight with a mass of 3 kg is dropped onto the piston from a height of 10 m. The entropy of the gas is 1.18 J/K and the change in the entropy of the environment is -1.18 J/K.

A cylindrical weight with a mass (m) of 3 kg is dropped, that is, its initial velocity (u) is 0 m/s and travels 10 m (s). Assuming the acceleration (a) is that of gravity (9.8 m/s²). We can calculate the velocity (v) of the weight in the instant prior to the collision with the piston using the following kinematic equation.

[tex]v^{2} = u^{2} + 2as = 2 (9.8 m/s^{2} ) (10m) \\\\v = 14 m/s[/tex]

The object with a mass of 3 kg collides with the piston at 14 m/s, The kinetic energy (K) of the object at that moment is:

[tex]K = \frac{1}{2} m v^{2} = \frac{1}{2} (3kg) (14m/s)^{2} = 294 J[/tex]

The kinetic energy of the weight is completely converted into heat transferred into the gas cylinder. Thus, Q = 294 J.

Given all the process is at 250 K (T), we can calculate the change of entropy of the gas using the following expression.

[tex]\Delta S_{gas} = \frac{Q}{T} = \frac{294 J}{250K} = 1.18 J/K[/tex]

The change in the entropy of the environment, has the same value but opposite sign than the change in the entropy of the gas. Thus, [tex]\Delta S_{env} = -1.18 J/K[/tex]

A cylindrical weight with a mass of 3 kg is dropped onto the piston from a height of 10 m. The entropy of the gas is 1.18 J/K and the change in the entropy of the environment is -1.18 J/K.

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Answer:

River esk the third one is righttt

Answer:  a.1.37  b.4.11 c.6.00  d.12.3

Explanation:

With regard to distilling the mixture of methanol and water using simple

distillation and fractional distillation, a statement that can be made that is

not true is that; Methanol and water form an azeotrope.

Reasons:

Azeotrope are liquid mixtures that have the property of a constant boiling

point due to the contents of the vapor are the same as the mixture.

Water when mixed with methanol form network structures. However,

methanol does not form a binary azeotrope with water.

Therefore, a statement that is not true is that methanol and water form an

azeotrope a mixture that has a constant boiling temperature.

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Answer: 2

Explanation:

Ba(OH)2 contains two oxygen atoms

BaSO4 contains four oxygen atoms.

This means that barium sulfate contains two more oxygen atoms than barium hydroxide in its formula.

Hope this helps!! :)

According to formula BaSO₄, Barium sulfate contains 2 more oxygen atom.

The correct option is (A) 2

Ba(OH)₂ has two oxygen atoms in it.

Four oxygen atoms may be found in BaSO₄.

This indicates that the formula of barium sulfate has two extra oxygen atoms than the formula of barium hydroxide.

Barium sulfate, often known as BaSO4, is a transparent white pigment that has a long history. It is produced by combining sulfuric acid with barium hydroxide and other sources of barium.

Chemically speaking, barium hydroxide has the formula Ba(OH)2. The monohydrate of barium, sometimes referred to as baryta or baryta-water, is one of the element's main compounds. The typical commercial form of monohydrate is this white granular substance.

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(a) The number of molecules contained by the balloon at the given condition is 6,438.97 moles.

(b) The mass of air in the balloon is 186.73 kg.

The given parameters;

The number of molecules contained by the balloon at the given condition is calculated as follows;

[tex]PV = nRT[/tex]

where;

[tex]n = \frac{PV}{RT} \\\\n = \frac{10,100 \times 1500}{8.314 \times 283} \\\\n = 6,438.97 \ moles[/tex]

The mass of air in the balloon is calculated as;

[tex]n = \frac{m}{M} \\\\m = nM\\\\m = 6,438.97\ moles \ \times \ 29 \ g/mol\\\\m = 186.73 \ kg[/tex]

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[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪  {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]

The Correct choice is ~ D

Solute is the substance that dissolves into another substance

Explanation:

filling air inside an empty o2 medal containers, if air is added, the air inside, creates volume inside.

due to heat, weather,... depending on what indoor or outdoor storage said containers r placed in,;

So, I can't give you an answer, due to lack of details..sorry...

Answer:

Mass Number

Explanation:

In nuclear physics, the sum of the numbers of protons and neutrons present in the nucleus of an atom.

Please vote brainliest!

Answer:

1. A/Thermal Energy

2. B/The particles within the system will have greater motion, and the temperature will increase.

3. C/Attractions occur due to electrostatic forces. When particles move fast enough, these forces can no longer keep particles together.

4. D/ For a phase change from solid to liquid, the bonds do not break completely and particles can still slide past each other.

5. D/ a sample of liquid benzene at 80ºC and a sample of gaseous benzene at 80ºC

Explanation:

I took the Test.

1. Internal energy associated with systems and particles is thermal energy. Thus, option A is correct.

The internal energy has been described as the energy that has been assessed by the molecules and bonds at the STP. Thermal energy has been the energy of particular molecules and the system comprising all the molecules have the summation of the thermal energy.

Thus, internal energy associated with systems and particles is thermal energy. Thus, option A is correct.

2. The addition of energy results in greater motion with an increase in temperature has been representation no phase change. Thus, option B is correct.

The addition of energy to the substance results in the increased motion of the particles. The energy higher than the threshold energy has been responsible for the phase change of the substance.

The addition of energy results in greater motion with an increase in temperature has been representation no phase change. Thus, option B is correct.

3. The movement of the particles under the gravitational attraction is not enough to hold the particles together at a longer distance. Thus, option B is correct.

The attraction has been the force that has been responsible for holding the particles in a molecule. Different attractions have a different levels of stability and strength.

The movement of the particles under the gravitational attraction is not enough to hold the particles together at a longer distance. Thus, option B is correct.

4. The phase change of the molecules has been mediated by overcoming the force of attraction that allows the molecules to move freely. The solid to liquid phase change has been mediated with the breaking of the attraction between the bonds allowing free movement.

Thus, statement 4 is incorrect, and option D is correct.

5. The kinetic energy has been the energy possessed by the moving molecules in the medium. The molecules in liquid and gas have been possessing the same energy at the same temperature, Thus, option D is correct.

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From the dilution formula, we have that at constant value of the solute, the volume of the solution is inversely proportional to the concentration.

The correct responses are;

Reasons:

The given parameters are;

The concentration of the KCl solution = 4% m/v

Taking the solution as solution of KCl

The volume of the solution in container 1 = Two times less than the volume of KCl solution.

[tex]V_{container \, 1} = \displaystyle \mathbf{ \frac{1}{2} \cdot V_{4\% \, solution}}[/tex]

The volume of the solution in container 2 = Two times larger compared to the volume of KCl solution.

[tex]V_{container \, 2} = \mathbf{\displaystyle 2 \times V_{4\% \, solution}}[/tex]

The volume of the solution in container 3 = Two times larger than the container two solution volume.

[tex]V_{container \, 3} = \displaystyle \mathbf{ 2 \times V_{container \, 2}}[/tex]

Therefore;

[tex]V_{container \, 3} = \displaystyle 2 \times 2 \times V_{4\% \, solution} = \mathbf{4 \times V_{4\% \, solution }}[/tex]

Part A Required:

a. To select the container that represent the dilution of the 4% solution to 2%

Solution:

The dilution formula is; C₁·V₁ = C₂·V₂

Therefore;

[tex]\displaystyle V_1 = \mathbf{\frac{C_1 \cdot V_1}{C_2}}[/tex]

C₁ =4%, C₂ = 2%, we get;

[tex]\displaystyle V_1 = \frac{4 \cdot V_1}{2} = 2 \cdot V_1[/tex]

The volume of the container that represents a 2% dilution is container 2

which is filled with a solution of a volume two times larger compared to the

KCl solution.

Part B:

Required:

The container diluted to a 1% m/v KCl solution.

Solution;

Using the dilution formula, we have;

C₁ = 4%, C₂ = 1%

Therefore;

[tex]\displaystyle V_1 = \frac{C_1 \cdot V_1}{C_2}[/tex]

[tex]\displaystyle V_1 = \frac{4 \cdot V_1}{1} = \mathbf{4 \cdot V_1}[/tex]

The volume of the solution is four times the volume of the 4% KCl solution, which is equivalent to the volume in container 3.

Possible parts of the question are;

Select the container that represents the dilution of the 4% (m/v) KCl solution to obtain the solutions that follows;

Part A: a 2% (m/v) KCl solution

Part B: a solution that is a 1% (m/v) KCl solution

Please see attached drawings

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Answer: O 2, 1,4

Explanation:

Answer:

No it has not.

Explanation:

The actual chemical compound has not changed, the materials have mixed but no reaction has taken place. Blowing the bubbles causes a physical change. Hope this helped!

Mixing soap and water and forming bubbles is a physical change as there is no change in composition.

Physical changes are defined as changes which affect only the form of a substance but not it's chemical composition. They are used to separate mixtures in to chemical components but cannot be used to separate compounds to simpler compounds.

Physical changes are always reversible using physical means and involve a change in the physical properties.Examples of physical changes include melting,boiling , change in texture, size,color,volume and density.Magnetism, crystallization, formation of alloys are all reversible and hence physical changes.

They involve only rearrangement of atoms and are often characterized to be changes which are reversible.

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