How do the key results indicate

Answer:

55.85 amu

Explanation:

Let A, B, C and D represent the four isotopes of element X.

The following data were obtained from the question:

Isotope A:

Abundance (A%) = 5.845%

Mass of A = 53.93961 amu

Isotope B:

Abundance (B%) = 91.75%

Mass of B = 55.93494 amu

Isotope C:

Abundance (C%) = 2.123%

Mass of C = 56.93539 amu

Isotope D:

Abundance (D%) = 0.2820%

Mass of D = 57.93328 amu

Average atomic mass of element X =.?

The average atomic mass of X can be obtained as follow:

Average Atomic mass = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100] + [(Mass of D × D%)/100]

Average Atomic mass = [(53.93961 × 5.845)/100] + [(55.93494 × 91.75)/100] + [(56.93539 × 2.123)/100] + [(57.93328 × 0.2820)/100]

= 3.15277 + 51.32031 + 1.20874 + 0.16337

= 55.84519 ≈ 55.85

Therefore, the average atomic mass of X is 55.85 amu

Answer:

To instill a high degree of personal honor, self-reliance, and confidence in each cadet by presenting a military environment in which cadets will be forced to rely upon themselves and their shipmates to study, work, and learn.

Answer: James Chadwick discovered neutral particles in the nucleus. So your answer is C

Explanation:

I just took a pretest and I had this same question and I got it right

Answer:

James Chadwick discovered neutral particles in the nucleus.

Answer: biotic is Living things in their ecological relations.

Explanation:

Answer:

all the below are ACIDS

Explanation:

1.HCOO- Formate

  HCOO- is a conjugate base.

2.HNO3- Nitric Acid

  Acid

3.CH3COOCH3: Methyl acetate

   Acid

4. HCOOH: Formic Acid

   Acid

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Answer:

The correct option is (D).

Explanation:

Uncertainty means lack of certainty in any calculations. It is the quantification of doubts after the calculations are done.

In this problem, we need to find the uncertainty in the measurement 0.0035 mg. There are 4 numbers after decimal. It means uncertain digit 1/10000 is the smallest scale division.

Hence, the uncertainty in the measurement 0.0035 mg is +0.0001 mg

Answer:

CH3CH2NH3+/CH3CH2NH2 would have the largest pKa

Explanation:

To answer this question we must know Kb of CH3CH2NH2 is 5.6x10⁻⁴, and for C6H5NH2 is 4.0x10⁻¹⁰. And the CH3CH2NH3+ and C6H5NH3+ are related with these substances because are their conjugate base. That means:

pKa of  CH3CH2NH3+ =  CH3CH2NH2;  C6H5NH3+ =  C6H5NH2

Also, Kw / Kb = Ka

Thus:

pKa of CH3CH2NH3+/CH3CH2NH2 is:

Kw / kb = Ka = 1.79x10⁻¹¹

-log Ka = pKa

pKa = 10.75

pKa of C6H5NH3+/ C6H5NH2 is:

Kw / kb = Ka = 2.5x10⁻⁵

-log Ka = pKa

pKa = 4.6

That means CH3CH2NH3+/CH3CH2NH2 would have the largest pKa

Answer:

buoyancy. ...

Explanation:

........

Answer:

buoyancy

Explanation:

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Answer:

Mass and density is the answer?

-78° Celsius is the temperature in units of degrees Celsius.

Temperature is the measure of hotness or coldness expressed in terms of any of several scales, including Fahrenheit and Celsius.

195 Kelvin = 195 - 273.15 = -78.15 Celsius.

-78° Celsius is the temperature in units of degrees Celsius.

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Answer:

C Qualitative Analysis.

Explanation:

Answer:

Self-reduction is a reaction in which no external reducing agent is required. It is called self-reducing because copper oxide itself reduced the copper sulfide to give copper and sulfur dioxide.

Answer:

1.03

Explanation:

You would take 0.00103 and move the decimal like this; 0001.03, we wouldn't have the zeroes in front of the one, as it can throw us off. Therefore, your answer would be 1.03.

Hope I helped! Don't hesitate to let me know if I made a mistake.

Answer:

Distance = 1500miles

time taken = 3 hours

speed of plane = distance/time taken = 1500/3= 500milesperhour

Explanation:

According to the distance formula , the speed of the plane is 500 miles per hour.

The speed of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit interval of time indicating that it is thus a scalar quantity.The average speed of an object in an interval of time is the distance traveled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as the duration of the time interval approaches zero. Speed is not the same as velocity.

Speed has the dimensions of distance divided by time. The SI unit of speed is the metre per second (m/s), but the most common unit of speed in everyday usage is the kilometre per hour (km/h) or in the US and the UK, miles per hour (mph).

Here, speed is calculated as distance /time= 1500/3= 500 miles per hour.

Thus, the speed of plane is 500 miles per hour.

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Answer:

128 neutrons

Explanation:

How many neutrons are there in 8 molecules of [tex]^{19} _9 F_2[/tex]?

Step 1: Calculate the number of neutrons in 1 atom of F.

The atomic number (z) of F is 9 and its mass number (A) is 19. We can calculate the number of neutrons using the following expression.

n⁰ = A - Z = 19 - 9 = 10

Step 2: Calculate the number of neutrons in 1 molecule of F₂.

1 molecule of F₂ contains 2 atoms of F. The number of neutrons in  1 molecule of F₂ is:

(8 n⁰/1 atom F) × (2 atom F/1 molecule F₂) = 16 n⁰/1 molecule F₂

Step 3: Calculate the number of neutrons in 8 molecules of F₂

8 molecule F₂ × 16 n⁰/1 molecule F₂ = 128 n⁰

Answer:

0.71 gal

Explanation:

Step 1: Given data

Density of Diesel (ρ): 0.839 g/mL

Mass of Diesel (m): 2.3 kg

Step 2: Convert "m" to grams

We will use the relationship 1 kg = 10³ g.

2.3 kg × (10³g/1 kg) = 2.3 × 10³ g

Step 3: Calculate the volume (V) of the Diesel sample

We will use the density formula.

ρ = m/V

V = m/ρ

V = 2.3 × 10³ g/(0.839 g/mL)

V = 2.7 × 10³ mL

Step 4: Convert "V" to L

We will use the relationship 1 L = 10³ mL.

2.7 × 10³ mL × (1 L / 10³ mL) = 2.7 L

Step 5: Convert "V" to gal

We will use the relationship 1 gal = 3.79 L.

2.7 L × (1 gal/3.79 L) = 0.71 gal

Answer:

2.3 kg x1000 g/kg = 2300 g

2300 g x 1 ml/0.839 g = 2741 ml

2741 ml x 1 L/1000 ml = 2.741 L

2.741 L x 1 gal/3.79 L = 0.72 gallons

Explanation:

Answer:

Living organisms breathe gases in the atmosphere.

Explanation:

Answer:

Living organisms breathe gases in the atmosphere.

Explanation:

Biosphere

the regions of the surface, atmosphere, and hydrosphere of the earth (or analogous parts of other planets) occupied by living organisms.

 Atmosphere

the envelope of gases surrounding the earth or another planet

Answer:

[tex]V=0.200L[/tex]

Explanation:

Hello,

In this case, since the volumetric capacity of the beaker is 200 cm³, by considering that 1000 cm³ equals 1 L, the liters are then computed via the following unit conversion:

[tex]V=200cm^3*\frac{1L}{1000cm^3}\\ \\V=0.200L[/tex]

Best regards.

Answer:

344.5764 torr

Explanation:

Molar mass of naphthalene = 128.2g/mol

Mass of naphthalene = 10.60 g

Carbon disulfide:

Molar mass= 76.14g/mol ;

volume = 155mL ;

density = 1.261 g/mL

Vapour pressure = 355.6 torr

Number of moles = mass / molar mass

CS2:

Mass = density × volume

Number of moles = (density × volume) / molar mass

Number of moles = (1.261 * 155) / 76.14 = (195.455 / 76.14) = 2.567 moles of CS2

Number of moles of C8H10:

Number of moles = 10.60 / 128.2 = 0.083 C8H10

Total number of moles :

2.567 + 0.083 = 2.65 moles

Mole fraction of each compound in solution :

CS2 :

2.567 / 2.65 = 0.969

C8H10:

0.083 / 2.65 = 0.031

According to Raoult's:

Psolution = Xsolvent × Posolvent

CS2 = solvent

Xsolvent = Mole fraction of solvent

Posolvent = Vapour pressure of pure solvent

Psolution = 0.969 × 355.6 torr = 344.5764 torr

The vapor pressure of the solution would be as follows:

[tex]344.5764[/tex] torr

Given that,

Vapor pressure of Carbon Disulfide [tex]= 355.6[/tex] torr

[tex]volume = 155mL ;[/tex]

[tex]density = 1.261 g/mL[/tex]

Naphthalene's mass [tex]= 10.60 g[/tex]

Naphthalene's molar mass [tex]= 128.2g/mol[/tex]

Now,

We know that

Number of moles [tex]= mass/molar mass[/tex]

Mass [tex]= density[/tex] × [tex]volume[/tex]

[tex]Number of moles =[/tex] [tex](density[/tex] × [tex]volume) / molar mass[/tex]

So,

Number of moles of Carbon Disulfide [tex]= (1.261[/tex] × [tex]155) / 76.14[/tex]

[tex]= (195.455 / 76.14)[/tex]

[tex]= 2.567[/tex] moles of Carbon Disulfide

Number of moles of Naphthalene:

Number of moles [tex]= 10.60 / 128.2[/tex]

[tex]= 0.083[/tex]

Now,

Total number of moles :

[tex]2.567 + 0.083[/tex]

[tex]= 2.65[/tex] moles

Mole fraction of each compound in solution :

Carbon Disulfide:

2.567 / 2.65

[tex]= 0.969[/tex]

Naphthalene

0.083 / 2.65

[tex]= 0.031[/tex]

According to Raoult's:

P[tex]solution = Xsolvent[/tex] × [tex]Posolvent[/tex]

Carbon Sulfide = Solvent

[tex]Xsolvent =[/tex] Mole fraction of solvent

[tex]Posolvent =[/tex] Vapour  pressure of the pure solvent

[tex]Psolution[/tex] [tex]= 0.969[/tex] × [tex]355.6 torr[/tex]

[tex]= 344.5764[/tex] torr

Thus, "[tex]344.5764[/tex] torr" is the correct answer.

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Answer:

[tex]Ksp=[Zn^{2+}]^3[PO_4^{3-}]^2[/tex]

Explanation:

Hello,

In this case, since the equilibrium dissociation of zinc phosphate is:

[tex]Zn_3(PO_4)_2(s)\rightleftharpoons 3Zn^{2+}(aq)+2(PO_4)^{3-}(aq)[/tex]

Due to the fact that only the zinc and phosphate ions are in aqueous state, the solubility product expression is written considering the law of mass action in which the concentration of each species is powered to the corresponding stoichiometric coefficient as follows:

[tex]Ksp=[Zn^{2+}]^3[PO_4^{3-}]^2[/tex]

Best regards.

Answer:

The answer is

Explanation:

In order to calculate the volume needed we use the formula

[tex]V_2 = \frac{C_1V_1}{C_2} [/tex]

where

C1 is the concentration of the stock solution

V1 is the volume of the stock solution

C2 is the concentration of the diluted solution

V2 is the volume of thevdiluted solution

From the question

C1 = 1.45 M

V1 = 25 mL

C2 = 0.0245 M

So we have

[tex]V_2 = \frac{1.45 \times 25}{0.0245} = \frac{36.25}{0.0245} \\ = 1479.59...[/tex]

We have the final answer as

Hope this helps you

Answer:

72 million because they needed to raise cash for its development

Explanation:

It is a known fact that at lunch Ethereum had only 72 million tokens in existence back in July 2015. In other to develop the Blockchain network further, the founder, Vitalik Buterin organized a fundraising event around July and August 2014.

Fast forward to the year 2020, Ether now has a total supply of about 112 million.

Answer:

Silicon tetrachloride

Dinitrogen tetroxide

The name of the compound SiCl₄ is named silicon tetrachloride and N₂O₄ is named dinitrogen tetroxide.

SiCl₄ is named silicon tetrachloride. It is composed of one silicon atom (Si) bonded to four chlorine atoms (Cl). The prefix "tetra-" indicates the presence of four chlorine atoms bonded to the central silicon atom.

N₂O₄ is named dinitrogen tetroxide. It consists of two nitrogen atoms (N) bonded to four oxygen atoms (O). The prefix "di-" indicates the presence of two nitrogen atoms, and the suffix "-tetraoxide" indicates the presence of four oxygen atoms.

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Answer:

total mass divided by its total volume

Explanation:

Answer:

The freezing point is -3.72 degrees Celsius

Explanation:

In this question, by assuming the complete dissociation of the salt, we want to calculate the freezing point of an aqueous 1 M NaCl solution .

We proceed as follows;

Firstly, we write the dissociation equation;

NaCl ——> Na+ + Cl-

So the number of ions present in the dissociation is 2. This means that the Vant Hogg factor also called I = 2

Mathematically;

ΔTf = Kf*m*i

m represents the molality which is given as 1

So by substituting the values, we have;

ΔTf = 1.86 * 1 * 2 = 3.72 degrees Celcius

The freezing point however is 0 - ΔTf = 0 - 3.72 = -3.72 degrees Celcius

[tex]\text{Hello there! :)}[/tex]

Answer:

[tex]\large\boxed{(B)}[/tex]

Elements on the periodic table that are the closest in characteristics are in the same group, or column.

Looking at the answer choices, the only two pairs of elements that are in the same group are (B) Al and Ga, as well as (D) F and I.

On the periodic table, Al (Aluminum) and Ga (Gallium) are only one period (row) away from each other, while F (Flourine) and I (Iodine) are 3 periods away.

***Periods determine the number of energy levels and other properties, so elements that are closer to each other would have more similar properties.

Therefore, Aluminum and Gallium contain the most similar chemical properties.

Answer: 343 K

Explanation:

To convert Celsius to Kelvin, you would add 273 to Celsius.

70°C+273=343 K

Now, we know that 70°C is 343 K.

Answer:

experiment showed that the atom is mostly empty space with a tiny, dense, positively-charged nucleus.

Explanation:srry im late but i dont be on it like that  hoped it helped tho srry

Answer:

By visiting other households with cats.

Explanation:

This will give Brian a variety of other houses and determine if it is truly cats or just alleries from other items. This is the most direct way to get Brian the answer he is looking for.

Answer:

c

Explanation:

i just did it