Why is the average atomic mass used when calculating grams of a
substance?
A. The exact weights of the isotopes are not known.
B. The elements in the substance are mixtures of their isotopes.
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C. The average atomic mass is known to more significant figures.
D. The number of isotopes in the sample is constantly changing.

Answer:

Describe what is happening within the system when it is at equilibrium in terms of concentrations, reactions that occur, and reaction rates.

Explanation:

The chemical equilibrium state is the state where the rate of forward reaction becomes equal to the rate of backward reaction.

At this stage the change in concentration of reactants becomes equal to the change in concentration of products.

The reaction will never cease.

That is the reason chemical equilibrium is called dynamic equilibrium.

So, forward and backward reactions will be taking place continuously at equal rates.

Answer:

true

Explanation:

As an atom with no charge have same number of proton and electrons

Answer:

What are your given options? I can't answer unless I know those :)

Explanation:

Answer: The [tex]K_{sp}[/tex] of [tex]AgCrO_{4}[/tex] is [tex]1.1 \times 10^{-12}[/tex].

Explanation:

Given: [tex][Ag^{+}] = 1.3 \times 10^{-4} M[/tex]

The reaction equation will be written as follows.

[tex]Ag_{2}CrO_{4} \rightleftharpoons 2Ag^{+} + CrO^{2-}_{4}[/tex]

This shows that the concentration of [tex]CrO^{2-}_{4}[/tex] is half the concentration of [tex]Ag^{+}[/tex] ion. So,

[tex][CrO^{2-}_{4}] = \frac{1.3 \times 10^{-4}}{2}\\= 0.65 \times 10^{-4} M[/tex]

The expression for [tex]K_{sp}[/tex] of this reaction is as follows.

[tex]K_{sp} = [Ag^{+}]^{2}[CrO^{2-}_{4}][/tex]

Substitute values into the above expression as follows.

[tex]K_{sp} = [Ag^{+}]^{2}[CrO^{2-}_{4}]\\= (1.3 \times 10^{-4})^{2} \times 0.65 \times 10^{-4}\\= 1.1 \times 10^{-12}[/tex]

Thus, we can conclude that the [tex]K_{sp}[/tex] of [tex]AgCrO_{4}[/tex] is [tex]1.1 \times 10^{-12}[/tex].

Answer:

Synthetic sponges are made of three basic ingredients: cellulose derived from wood pulp, sodium sulphate, and hemp fiber. Other materials needed are chemical softeners, which break the cellulose down into the proper consistency, bleach, and dye.

Explanation:

IDK, BUT HOPE IT HELPS?

Un paciente que recibe suero fisiológico a una velocidad de infusión de 1 gota = 0,05 ml por segundo recibirá en 5 horas 790 grs de NaCl, tomando en cuenta que la solución acuosa de suero fisiológico contiene 0,878 grs/mL de NaCl.

Explicación

Los datos que se tienen son:

Ya establecidas las respectivas conversiones se trata de determinar qué volumen de suero fisiológivo se ha infundido al paciente en 5 horas

Si se infunden 3 ml cada minuto, ¿Cuánto se habrá infundido en 300 minutos?

3 ml ______________ 1 min

X ________________ 300 min

X = (300 min x 3 ml) / 1 min

X = 900 ml

Como en 5 horas el paciente ha recibido 900 ml de suero, se determina la cantidad de NaCl que se encuentra en ese volumen de líquido

0,878 grs __________ 1 ml

X ________________ 900 ml

X = (900 ml x 0,878 grs) / 1 ml

X = 790 grs de NaCl

Answer:

See explanation

Explanation:

There are three modes of heat transfer; conduction, convection and radiation.

Conduction refers to the transfer of heat without the actual movement of the particles of matter.

Convection is the transfer of heat by the actual movement of the particles of matter.

Radiation is the transfer of heat without a material medium.

Hence the three modes of heat transfer differ in the actual mechanism by which heat energy is transferred as shown above.

Answer:

The movement of molicules

The movement of a fluid

Electromagnetic Waves

Explanation:

Trust me

Answer:

18,9g de hexano son necesarios

Explanation:

Basados en la ley de Raoult, la presión de vapor ejercida por una solución es:

P = P°*Xsolvente

Donde P es la presión de la solución deseada = 700mmHg, P° la presión de vapor de vapor del benceno = 1atm = 760mmHg y X es la fracción molar del solvente (Benceno).

Reemplazando:

700mm Hg = 760mmHg * X(Benceno)

0.9211 = X(Benceno)

La fracción molar de benceno se define como:

X = Moles benceno / Moles benceno + Moles hexano

Moles benceno -Masa molar: 78g/mol-

200g * (1mol/78g) = 2.5641 moles benceno

X = Moles benceno / Moles benceno + Moles hexano

0.9211 = 2.5641 moles benceno / 2.5641 moles benceno + Moles hexano

0.9211moles Hexano + 2.3618 = 2.5641

0.9211*Moles Hexano = 0.2023

Moles hexano = 0.2023/0.9211 = 0.2196 moles hexano.

Masa Hexano -Masa molar: 86g/mol-

0.2196 moles hexano * (86g/mol) =

La cantidad de hexano (C6H14) que se debe agregar a 200 g de benceno para permitir que la presión de vapor se convierta en 700 mm de Hg sería:

18.9 g

Usando la ley de Raoult, la presión de vapor que libera una solución se encuentra por:

P = P ° × X disolvente  

Donde (P) denota la presión de la solución deseada

P ° denota la presión de vapor del benceno y

X denota la fracción molar del disolvente (benceno).

En el caso dado,

(P) = 700 mmHg,

P° = 1atm = 760mmHg

Fracción molar de benceno = 0,9211           (∵ 700/760)

La fracción molar de benceno (X)  = Moles de benceno/Moles de benceno + Moles de hexano

Moles de benceno - Masa molar: 78g / mol -  200 g × (1 mol / 78 g)

= 2.5641 moles de benceno

X = Moles de benceno/Moles de benceno + Moles de hexano

0.9211 = 2.5641 moles Benceno/2.5641 moles Benceno + Moles de Hexano

⇒ 0,9211 × moles de Hexano + 2,3618 = 2,5641    

⇒ 0.9211 × moles de Hexano = 0.2023

∵ Moles de Hexano = 0.2023/0.9211

[tex]= 0.2196 moles[/tex]

[tex]Hexane mass - Molar mass = 86g/mol - 0.2196 mole hexane[/tex] × [tex](86g/mole)[/tex]

[tex]= 18.9g[/tex]

Por tanto, 18,9 g es la respuesta correcta.

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Answer:

Wt Avg At Mass = 39.0229 amu

Explanation:

The Weight Average Atomic Mass in atomic mass units (amu) is the sum of the Weight Average Mass contributions of each isotopic mass. That is,

Wt. Avg. At. Mass (amu) = ∑ Wt. Avg. Contributions of each isotopic mass

Wt. Avg. Contribution = fractional abundance x isotopic mass(amu)

For this problem data:

Isotope   %Abundance     fractional         Isotopic             Wt Avg Isotopic

                                        abundance      mass(amu)        Contribution (amu)

   1                  9.67%           0.0967               38                      3.6746 amu

   2               78.68%           0.7868               39                    30.6852 amu

   3                 11.34%           0.1134                 40                      4.5360 amu

   4                  0.31%           0.0031                41                       0.1271  amu

________________________________________________________

Wt. Avg. Atomic Mass (amu) = ∑ Wt. Avg. Contributions  =  39.0229 amu

Answer:

C thermal

Explanation:

Answer:

Amount of oxygen needed is 5,000 liter

Explanation:

Given:

Percent of air in oxygen = 1%

Find:

Oxygen if 50 liter of wind

Computation:

Oxygen if 50 liter of wind  = 50 liter wind[100% / 1% ]

Oxygen if 50 liter of wind  = 50 liter wind[100]

Oxygen if 50 liter of wind  = 50[100]

Oxygen if 50 liter of wind  = 5,000

So,

Amount of oxygen needed is 5,000 liter

Answer:

0.3kg

Explanation:

Answer:

Explanation:

Lead Monoxide: PbO

Nitric Acid: HNO3

PbO + 2 HNO3 ---> Pb(NO3)2 + H2O

Answer:

Explanation:

mono mean single so lead monoxide is PbO

nitric acid is HNO3

both Pb n O are double-charged while H n NO3 are single

so balanced eqn is:

PbO + 2HNO3 -> Pb(NO3)2 + H2O

The question is incomplete, the complete question is;

As Danny was pouring cereal for his breakfast, he noticed that the cereal box says that the cereal contains 5 milligrams of iron per serving. Danny decided to perform an experiment to test this claim. He found that the cereal contains 4.6 milligrams of iron per serving. Based on Danny's measurement, the value reported on the label is ( CORRECT OR INCCORECT) because A: (IT IS DIFFERENT FROM THE VALUE DANNY MEASURED) B: (IT IS REORTED TO THE NEAREST MILLIGRAM) C: (IT USES THE SAME UNITS THAT DANNY USED).

Answer:

CORRECT because IT IS REORTED TO THE NEAREST MILLIGRAM

Explanation:

In mathematics, values may be rounded up or down as required. In the case of this measurement of cereals by Danny, it is customary to measure the amount of iron per serving to the nearest milligram.

As such, even though Danny found out that the actual amount of iron per serving in the cereal is 4.6 milligrams, the value reported on the cereal box is still correct because it was reported to the nearest milligram hence the value had to be rounded up.

Answer:

No

Can't understand.

Pls follow me and Mark as brainliest Plsssssssss.

Answer:

element.... ....

.....

Answer:

D. 2

Explanation:

On the right side of the equation:

Al has 1, Zn has 3, NO3 has 6

But on the left side:

Al has 1, Zn has 1, NO3 has 3

1. So, if we add a coefficient of 2 to Al(NO3)3, then NO3 now has 6-which is what it needs.

2. But now the Al on the right side of the equation is not balanced, so give it a coefficient of 2.

3. To make the Zn balance, just add a coefficient of 3 on the left side of the equation.

Which leaves us with:

2Al + 3Zn(NO3)2 --> 2Al(NO3)3 + 3Zn

And now there are the same number of each compound on both sides of the equation.

Good luck! If you have any questions on this answer leave a comment :)

Answer: 22.7848% F or 23%

Explanation: %F = 3.6g/15.8g • 100% = 22.7848% F

The percentage composition of hydrogen in the given sample is equal to 31%.

The percentage composition of a given compound can be described as the ratio of the quantity of each element to the total quantity of individual elements in the compound multiplied by 100. The quantity can be measured in terms of grams of the elements present in the sample.

The percent composition is expressed in its composition in terms of all the elements present. Thus, it helps in the chemical analysis of any given compound.

The percentage composition is expressed using the following formula,

Percentage composition of E = (E/T) × 100

Where E represents the total quantity of element E present in the compound and T represents the total quantity of all the elements present in the compound.

Given, the mass of the F, H, and C is 3.60g, 4,90 g, and 7.30 g respectively.

The total mass of the given sample = 15.8 g

The mass of the hydrogen in the sample = 4.90 g

The percent composition of H = (4.90/15.8) × 100 = 31 %

Therefore, the percent composition of hydrogen in this sample is 31%.

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Cu(s) + Ni(NO3)2(aq) ⇒Ni(s) + Cu(NO3)2(aq)

The answer is option B.

Electrochemical or hobby series when the electrodes (metals and non-metals) in touch with their ions are organized on the idea of the values of their preferred discount potentials or standard oxidation potentials, the resulting series is called the electrochemical.

The electrochemical series is built up by means of arranging various redox equilibria so as of their fashionable electrode potentials (redox potentials). The maximum poor E° values are placed at the pinnacle of the electrochemical series, and the maximum wonderful at the lowest.

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Answer:

3 Protons, 2 Neutrons, & 3 Electrons. Is the charge of this atom positive, negative, or neutral?

Explanation:

Put these atoms in order from most negative overall charge to least negative

overall charge.

11 Atom X: 104 protons, 102 electrons

11 Atom B: 24 protons, 18 electrons

1 Atom Q: 15 protons, 16 electrons

11. Atom P: 7 protons, 10 electrons

Answer:

True

Explanation:

A physical change is a change of state. So when ice melts it changes from a solid to a liquid so it is a physical change

Answer:

39.02

Explanation:

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

Isotope A:

Mass of A = 38

Abundance of A (A%) = 9.67%

Isotope B:

Mass of B = 39

Abundance of B (B%) = 78.68%

Isotope C:

Mass of C = 40

Abundance of C (C%) = 11.34%

Isotope D:

Mass of D = 41

Abundance of D (D%) = 0.31%

Average atomic mass of X =?

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

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

= [(38 × 9.67)/100] + [(39 × 78.68)/100] + [(40 × 11.34)/100] + [(41 × 0.31)/100]

= 3.6746 + 30.6852 + 4.536 + 0.1271

= 30.02

Thus, the average atomic mass of X is 39.02

Answer:

A. Salt, hope its helped

Explanation:

For both men and women, the basics of a balanced diet are the same. Men have higher caloric requirements than women since they have a bigger body (both in height and weight) and more muscular mass.

So, Men needs more energy.

50 year old woman require less energy than 50 year old man.​

housefly

Explanation:

Because it one of the affective vector of disease carrier and it always roam towards wastes and dirty materials likely to get attracted . And it carries contagious disease from hospitals , infected patients , etc .

Answer:

Location 2 will cost the least to the company to mine.

Explanation:

a) Data and Calculations:

Locations  Cost of land     Cost of       Cost of mining      Time taken to

                                        equipment   and reclamation    mine the area

1                 $100,000      $10,000         $5,000 per day        30 days

2                 $35,000       $6,000          $4,500 per day        45 days

3                 $30,000       $7,500          $3,500 per day       120 days

4                 $40,500       $8,000          $7,000 per day        65 days

Locations  Cost of land     Cost of       Cost of mining                      Total

                                        equipment   and reclamation                    Costs

1                 $100,000      $10,000         $150,000 ($5,000 * 30)  $260,000

2                 $35,000       $6,000         $202,500 ($4,500 * 45)   $243,500

3                 $30,000       $7,500         $420,000 ($3,500 * 120)  $457,500

4                 $40,500       $8,000         $445,000 ($7,000 * 65)   $503,500

Answer:

any 5 ways to prevent earth are:

1.using ( 3R) principles Reduce, reuse, and recycle.

2.Educate yourself

3.Conserve water resources and other natural resources

4.Use long-lasting light bulbs.

5.stop deforestation and start afforestaion