which of the following is least soluble in water?group of answer choicesionic compoundsnonpolar moleculeshydrophilic compoundspolar molecules

5 ppm of Cr means 5 mg is present in 1 L of water. Then, 1000 g of water is containing 5 mg or 0.005 g of chromium.

PPM or part per million is a term used to express the concentration of a solution. 1 ppm is equal to 1 mg of the solute in 1000 ml or in 1 L of the solution.

ppm  = weight of solute/mass of solution ×10⁶. = mg/L

ppm is used to express very minute quantity of ay sample. Usually used in the concentration of heavy metals in water.

It is given that the concentration of Cr in water is 5 ppm, which means 5 mg per one liter of water. 1 l of water is 1000 ml or 1000 g of water. Hence, 1000 g of water contains 5 mg or 0.005 g of Cr.

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The electron is moving from energy level 2 to energy level 1 the ground state then the electron emits a photon of EMR. Therefore, option C is correct.

The set distances from an atom's nucleus where electrons may be found are referred to as energy levels. In an atom, the small, negatively charged electrons orbit the central, positively charged nucleus.

The energy of the electron drops when it changes levels, and the atom releases photons. The emission of the photon occurs as the electron transitions from a higher to a lower energy state.

Thus, option C is correct.

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Formaldehyde is a molecule with the chemical formula CH2O. It consists of a central carbon atom bonded to two hydrogen atoms and an oxygen atom, with a double bond between the carbon and oxygen atoms. The relative electronegativity values of the elements involved in formaldehyde are as follows:

• Carbon: 2.55

• Hydrogen: 2.20

• Oxygen: 3.44

Electronegativity is a measure of an atom's ability to attract the electrons towards itself in a covalent bond. In a covalent bond between two different atoms, the electrons are shared between them, but they may not be shared equally. In formaldehyde, the oxygen atom is more electronegative than the carbon atom. Therefore, the oxygen atom attracts the shared electrons in the double bond more strongly towards itself, resulting in a greater electron density around the oxygen atom. This creates a partial negative charge on the oxygen atom and a partial positive charge on the carbon atom. Similarly, the hydrogen atoms in formaldehyde have a lower electronegativity than the carbon atom. Therefore, the electrons in the C-H bonds are shared unequally, with a partial negative charge on the hydrogen atoms and a partial positive charge on the carbon atom.

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The molar solubility of CdF₂ in pure water is 0.0585M, and adding NaF decreases this solubility because the equilibrium shifts to favor the precipitation of some CdF₂. The correct option is A.

According to the statement, the option that identifies the molar solubility of CdF₂ in pure water and explains the effect that the addition of NaF has on this solubility is [CdF₂]eq = [Cd₂+]eq = 0.0585 M (since the solubility product expression for CdF₂ gives Ksp = [Cd₂+][F-]², and F- is in excess).

The molar solubility of CdF₂ in pure water can be determined by calculating the concentration of Cd₂+ and F− ions in the saturated solution, and then using the stoichiometry of the equilibrium reaction to determine the concentration of CdF₂ that would dissolve in pure water.

From the equilibrium equation: CdF₂(s) ⇄ Cd₂+(aq) + 2F−(aq), we know that for every mole of CdF₂ that dissolves, 1 mole of Cd₂+ and 2 moles of F− ions are produced.

The effect of adding NaF to the saturated solution can be explained by the common ion effect. When NaF is added, it provides additional F− ions, which are already present in the saturated solution, and thus increases the concentration of the common ion.

This leads to a shift in the equilibrium to the left, causing more CdF₂ to precipitate out of solution until a new equilibrium is established. As a result, the molar solubility of CdF₂ in the solution decreases.

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Complete question:

CdF₂(s)⇄Cd₂+(aq)+2F−(aq) A saturated aqueous solution of CdF₂ is prepared. The equilibrium in the solution is represented above. In the solution, [Cd₂+]eq=0.0585M and [F−]eq=0.117M. Some 0.90MNaF is added to the saturated solution. Which of the following identifies the molar solubility of CdF₂ in pure water and explains the effect that the addition of NaF has on this solubility?

a. The molar solubility of CdF₂ in pure water is 0.0585M, and adding NaF decreases this solubility because the equilibrium shifts to favor the precipitation of some CdF₂.

b. The molar solubility of CdF₂ in pure water is 0.0585M, and adding NaF has no effect on the solubility because only changes in temperature can increase or decrease the molar solubility of an ionic solid.

c.The molar solubility of CdF₂ in pure water is 0.117M, and adding NaF decreases this solubility because the equilibrium shifts to favor the precipitation of some CdF₂.

d. The molar solubility of CdF₂ in pure water is 0.176M, and adding NaF increases this solubility because the Na+ ions displace the Cd₂+ ions, causing the equilibrium to shift to favor the products.

the outcome of combining an alkyne with one equivalent of hcl is st -CEC-H + 1H-CI. 3-methyl-1-butyne 2-chloro-3-methyl-1-butene.

An alkyne is a type of hydrocarbon with a triple bond between two carbon atoms, which makes it unsaturated and more reactive than its corresponding alkane or alkene. Alkynes have the general formula CnH2n-2 and can have multiple triple bonds, giving rise to a range of isomers with different properties. Alkynes are used in many industrial processes, such as in the production of polymers, solvents, and pharmaceuticals, and are also important intermediates in organic synthesis. Alkynes can undergo various types of reactions, such as addition, substitution, and polymerization, and their reactivity can be modulated by the choice of substituents, reaction conditions, and catalysts. Alkynes are also of interest in the field of materials science, as they can form strong covalent bonds with metals and semiconductors, and can be used as building blocks for molecular electronics and nanotechnology.

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In a redox reaction, there is a transfer of electrons

The question is incomplete but it seems to have something to do with redox reactions.

A balanced redox reaction is a chemical equation that represents a redox (reduction-oxidation) reaction with the same number of atoms of each element on both the reactant and product sides and the same total charge on both sides. In a redox reaction, there is a transfer of electrons from one substance (the reducing agent) to another substance (the oxidizing agent).

In order to balance a redox reaction, you need to balance the number of atoms of each element in the reaction, and also balance the charges.

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To calculate the heating value of both solid and liquid fuels, one uses a bomb calorimeter. It is made up of a powerful steel shell called a bomb. It is composed of a base that holds the platinum cross.

What exactly is a solid defined as?

It seems evident what a solid is; a solid is typically thought of as hard and firm. However, closer examination makes the term less clear. For instance, a butter cube is unmistakably a solid since it becomes hard after being kept in a refrigerator. Having stayed on the

A crystalline solid is what?

A solid that has its component atoms and molecules (or occasionally ions) arranged in a crystalline structure microscopic structure is referred to as a crystal lattice (also referred as a crystal). A homogeneous microscopic structure known as a crystal lattice extends across every point of the crystalline solid.

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The pH is determined by the relative amounts of acid and base in each circumstance.

a) Before addition of HBr;

Number of moles of C5H5N = 25/1000 L × 0.180 M = 0.0045 moles

pOH = -log[0.0045 M]

pOH = 2.35

pH = 14 - 2.35 = 11.65

b) After addition of 12.5 mL of HBr;

Since the reaction is 1:1

Number of moles of HBr = 12.5/1000 L × 0.180 M = 0.00225 moles

The HBr is the limiting reactant

Amount of excess acid = 0.0045 M - 0.00225 = 0.00225 moles

Total volume of solution = 25mL + 12.5 mL = 37.5mL or 0.0375 L

molarity of excess H+ = 0.00225 moles / 0.0375 L = 0.06 M

pH = - log[0.06 M]

pH = 1.22

c) After addition of 24.0 mL of HBr;

Number of moles of acid = 24/1000  × 0.180 M = 0.00432 moles

Number of moles of excess acid =  0.0045 moles  - 0.00432 moles = 0.00018 moles

Total volume of solution =  24.0 mL +  25.0 mL = 49mL or 0.049 L

Molarity of excess acid = 0.00018 moles/ 0.049 L = 0.00367 M

pH = -log[0.00367 M] = 2.4

d) After addition of 25.0 mL of HBr

Number of moles of acid = 25/1000  × 0.180 M = 0.0045 moles

We have an equal number of acid and base hence pH = 11.65

e) After addition of 34.0 mL of HBr;

Number of moles of acid = 34/1000  × 0.180 M =0.00612 moles

We can see that the base is the limiting reactant.

Number of moles of excess base = 0.00162 moles

Total volume of solution = 34 mL + 25 mL = 59mL or 0.059 L

Molarity of excess base = 0.00162 moles/0.059 L = 0.027 M

pOH = -log[ 0.027 M]

pOH = 1.56

pH = 14 - 1.56 = 12.44

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Answer:          5 × 10^3 g

Or, without significant figures, 5000 g.

To find the mass when given volume and density, multiply the volume with density.

We can solve using dimensional analysis or the 'cancelling out units' method.

[tex]m = \frac{50.0\ mL}{1}*\frac{100\ g}{1\ mL}[/tex]

[tex]m = \frac{50.0}{1}*\frac{100\ g}{1}[/tex]          Since mL is in the top and bottom, they cancel out.

[tex]m = 5000\ g[/tex]                 Multiply to find the answer.

[tex]m = 5 * 10^{3}\ g[/tex]              Write the answer with significant figures.

Therefore, the mass of 50.0 mL of water is 5 × 10^3 g.

This is the same as 5000 g if we do not consider significant figures.

If we use significant figures in this answer, we only keep 1 significant figure. When multiplying numbers, the final answer will have the same amount of significant figures as the numbers in the question with the least amount of significant figures.

If the numbers in the question have different amounts of significant figures, we will take the least amount of significant figures from the problem.

We had two numbers from the problem and they had different amounts of significant figures:

So, our final answer should only have 1 significant figure.

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Based on the mass of 1 mole of nitrogen atoms, 7.55 x 10²³ atoms of nitrogen have a mass of 17.56 grams.

The number of atoms in 1 mole of nitrogen = 6.02 * 10²³ atoms

The mass of 1 mole of atoms of nitrogen = 14 g

Hence, 6.02 * 10²³ atoms has a mass of 14.01 g

Mass of 7.55 x 10²³ atoms = 14.01 g/mol * 7.55 x 10²³ / 6.02 * 10²³

The mass of 7.55 x 10²³ = 17.56 g

So,7.55 x 10²³ atoms of nitrogen have a mass of 17.56 grams.

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The formula given relates the frequency of the photon emitted to the difference in energy levels of the hydrogen atom. The energy of the photon is given by

E = hν

where h is Planck's constant and ν is the frequency.

Part A:

         v~ = RH(1/12 - 1/22) = 3.28984 x 1015 cm-1

         v~ = RH(1/22 - 1/32) = 1.09737 x 1015 cm-1

          v~ = RH(1/32 - 1/42) = 4.34013 x 1014 cm-1

To find the highest value of energy (E) for each series, we can use the relationship E = hν. Using Planck's constant (h) and the highest frequency (v~) for each series, we get:

Hence, the answer is,

         v~ = RH(1/12 - 1/22) = 3.28984 x 1015 cm-1

         v~ = RH(1/22 - 1/32) = 1.09737 x 1015 cm-1

          v~ = RH(1/32 - 1/42) = 4.34013 x 1014 cm-1

Write a short note on the hydrogen spectrum.

The hydrogen spectrum refers to the pattern of lines that are observed when the emission spectrum of hydrogen is analyzed. It is caused by the excitation of electrons in hydrogen atoms, which emit light of specific frequencies as they return to lower energy states. The hydrogen spectrum consists of several series of lines, including the Lyman, Balmer, and Paschen series, which correspond to different electron transitions. The study of the hydrogen spectrum played a crucial role in the development of quantum mechanics and our understanding of atomic structure.

To find the highest value of energy (E) for each series, we can use the relationship E = hν. Using Planck's constant (h) and the highest frequency (v~) for each series, we get:

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An ionic compound comprised of Na+ and Cl is sodium chloride. An anion is a negative charges chlorine ion (Cl) and a cation is a positive sodium ion (Na+).

The sodium and chlorine ions exert an electric pull on one another when one sodium electron is transferred to a chlorine ion, binding the sodium and chlorine molecules together.

Because it attracts objects to itself from any distance, gravitational force is a very well-known example of attraction. More details regarding how this force operates are provided by Newton's global law of gravity.

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The energy value to kilocalories (kcal) would be 32.5 kcal.

One kilogram of water requires one kilocalorie (1 kcal, or 1000 calories) of heat energy to raise its temperature by one degree Celsius (°C). Joule is the SI-standard unit for energy (J). About 4.18 calories make up one kcal.

The phrase used to describe how much energy is needed to raise a liter of water's temperature by one degree Celsius at sea level. The term "calorie" is frequently used in nutrition terminology to describe a unit of dietary energy.

Let the equation be

1 kJ = 1,000 J

1 cal = 4.184 J

1 kcal = 1,000 cal

136 kj x 1000j/1kj = 1.36 x [tex]$$10^5[/tex] J

simplifying the equation, we get

1.36 x [tex]$$10^5[/tex] J x 1 cal/4.184J = 32, 500

32500 cal x 1 kcal/1,000 cal = 32.5 kcal.

Therefore, the energy value to kilocalories (kcal) would be 32.5 kcal.

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The tropical regions of earth contains the highest concentration of water vapor and higher altitudes and poles have the lower water vapor concentration.

Lower atmospheric water vapor molecules absorb heat generated from the Earth's surface. In turn, the water vapor molecules emit heat in all directions. The Earth's surface receives some of the heat back.

In the tropics, as the seasons change, a band of extremely humid air sways both north and south of the equator. The Intertropical Convergence Zone, where the easterly trade winds from either hemisphere meet and create almost daily thunderstorms and clouds, includes this ring of dampness.

Water vapor concentrations are higher farther from the equator in the summer-experienced hemisphere and lower in the winter-experienced one.

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If q > Keq, it means that the reaction quotient, q, has a higher numerical value than the equilibrium constant, Keq and the system is not at equilibrium and will produce more reactants to reach equilibrium (shift to the left).

Therefore, the system is not at equilibrium and will shift in the direction that reduces the value of q and increases the value of Keq, which is toward the side of the reaction with fewer products and more reactants.

In this case, the system will shift to the left (produce more reactants) to reach equilibrium. This suggests that there is an excess of products or a deficiency of reactants in the system compared to what would be present at equilibrium.

Hence the correct option is A.

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The pH value of the water decreased: indicating that it became more acidic compared to the first test.

During the experiment, the student blew bubbles into the water, which introduced carbon dioxide. Carbon dioxide reacts with water to form carbonic acid, a weak acid that can lower the pH of the water. As a result: the pH value of the water decreased, indicating that it became more acidic.

This is because the concentration of hydrogen ions, which determine acidity, increased in the water. The change in pH value may have implications for the organisms living in the water, as different pH levels can affect their survival and growth. Therefore understanding the effects of human activities, such as blowing bubbles into water, on pH levels is important for maintaining the health of aquatic ecosystems.

This question should be given as:

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The number of moles in 2.3 grams of sodium atom is 0.1 moles and is calculated by formula, mass/molar mass.

Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.

It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.It is given as,mass/molar mass= 2.3/23=0.1 moles

Thus, there are 0.1 moles in 2.3 grams of sodium.

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The mechanism of the reactions of both the subparts of the questions is below:

A)The formation of the acylium ion from the reaction between acetyl chloride and aluminium chloride can be described by the following mechanism:

Step 1: Formation of the complex

AcCl + AlCl3 → [AcCl-AlCl3]

Step 2: Deprotonation to form the acylium ion

[AcCl-AlCl3] → Ac+ + AlCl4-

In step 1, the acetyl chloride molecule reacts with aluminium chloride to form a complex. In step 2, the complex undergoes deprotonation to form the acylium ion, which is stabilized by the aluminium chloride.

(b) The mechanism for the Friedel-Crafts acylation of bromobenzene using the acylium ion formed in (a) can be described by the following steps:

Step 1: Formation of the complex

Ac+ + AlCl4- → [Ac-AlCl4]

Step 2: Attack of the ortho-carbon of bromobenzene

C6H5Br + [Ac-AlCl4] → C6H4Br-2-COCH3 + AlCl3

Step 3: Regeneration of the catalyst

AlCl3 + [Ac-AlCl4] → AcCl + AlCl4-

In step 1, the acylium ion formed in (a) reacts with aluminium chloride to form a complex. In step 2, the complex reacts with bromobenzene, and the ortho-carbon attacks the carbonyl carbon of the acylium ion to form a new carbon-carbon bond. In step 3, the catalyst is regenerated, and acetyl chloride is produced as a byproduct.

The arrow formalism for the three steps can be written as follows:

Step 1:

Ac+ AlCl4- [Ac-AlCl4]

↑ ↓ ↑

Step 2:

C6H5Br [Ac-AlCl4] C6H4Br-2-COCH3 AlCl3

↑ ↓ ↑ ↑

Nucleophile Electrophile Product Catalyst

Step 3:

AlCl3 [Ac-AlCl4] AcCl AlCl4-

↑ ↓ ↑ ↓

Catalyst Complex Byproduct Catalyst

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Separation into two diametrically opposed social, political, or religious movements.

Polarization, a property of transverse waves, describes the geometric orientation of the oscillations The direction of the oscillation in a transverse wave is the opposite of the wave's motion direction. A simple example of a polarised transverse wave is vibrations along a taut string, as a guitar string. Depending on how the string is pulled, the vibrations can be horizontal, vertical, or at any angle perpendicular to the string. Since the displacement of the oscillating particles always occurs in the direction of the wave's propagation, polarisation does not occur in longitudinal waves, such as sound waves in a liquid or gas.

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The chemical formula of pamitoleic acid is CH₃(CH₂)5CH=CH(CH₂)₇COOH. The structure of pamitoleic acid is given in the image attached below.

Palmitoleic acid has been known to have a lot of beneficial effects on insulin sensitivity, cholesterol metabolism, and hemostasis. It has been concluded that palmitoleic acid may prevent beta-cell apoptosis induced by glucose or saturated fatty acids.

Recently, studies have reported that palmitoleic acid is useful in treating disorders related to skin hyperpigmentation, fibrosis and as an adjuvant in formulations for the treatment of secondary infections caused by gram-positive bacteria.

Palmitoleic acid is one of the most common acids which is found in omega-7 fatty acids.

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There are 6.7 * 10^23 oxygen atoms

The mole is a unit of measurement in chemistry used to express amounts of a chemical substance. One mole is defined as the amount of a substance that contains Avogadro's number of entities, which is approximately 6.022 x 10^23 entities

The first step is to get the number of moles of the compound.

Number of moles =85 grams/602 g/mol

= 0.14 moles

Then we have the number of oxygen atoms as;

 0.14 moles * 8 * 6.02 * 10^23

= 6.7 * 10^23 oxygen atoms

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Carboxylic acids are acidic due to the presence of the carboxyl group. They can react with bases to form salts and water. Alkenes, on the other hand, are not acidic.

Alkenes have a carbon-carbon double bond (-C=C-), while carboxylic acids have a carboxyl group (-COOH). You can identify the functional group by looking at the molecular formula or by using spectroscopic techniques like infrared (IR) spectroscopy.

Carboxylic acids have higher boiling points than alkenes due to the presence of hydrogen bonding between carboxylic acid molecules.

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A chemical system is defined as a system at which equilibrium can be temporarily shifted out of equilibrium by adding or removing one or more of the reactants or products.

Le Chatelier`s Principle states that, "when a system at equilibrium is subjected to a change in temperatures, pressure, or concentration of a reactant or product, the system will, if possible shift its equilibrium position so as to partially counteract the effect of the change".

In equilibrium shifting, if the system gets darker red in color, then the equilibrium must be shifting to the right (i.e., towards producing more of the colored product). If the color of the system gets fainter (i.e., or disappears altogether), then the equilibrium must be shifting towards the left (toward the colorless components).

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Acid is sour taste, corrosive and has lots of H+, while base is soapy and has lots of OH-. A pH is degree to measures how acid or base a solution is. The more H+ ions, the more acidic it is and the lower the pH will be. 

The terms acid and base describe chemical characteristics of the substances. The properties of acids are as follow :

For example : lemon, vinegar and others

While base (alkalies) has these properties :

For example : soap and many more

To measure the strength of the acids and bases, we can see from the pH scale. pH stands for potential or power of hydrogen. The pH scale is range from 0 to 14. Acids have a pH below 7, bases have a pH above 7 while pH 7 is said to be neutral.

Thus, the more H+ ions, the more acidic it is and the lower the pH will be. 

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C): Pectin is a heteropolysaccharide.

Pectin is a heteropolysaccharide, which is a complex carbohydrate made up of different types of monosaccharides. It is commonly found in the cell walls of plants and is used as a gelling agent in the food industry. Amylopectin and cellulose are both homopolysaccharides, meaning they are made up of only one type of monosaccharide (glucose). Chitin is a polymer of N-acetylglucosamine, which is a type of amino sugar, but it is not classified as a heteropolysaccharide.

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The variables that are not state functions are m (mass), q (heat), and w (work).

Work is an activity that requires physical or mental effort and is done in exchange for money or other rewards. It can also be seen as an exchange of energy, where an individual puts in effort in order to achieve a desired outcome. Work can be done in a variety of fields and can range from manual labor to professional jobs. It is an important part of many people's lives and can be a source of fulfillment and satisfaction, as well as providing a means of economic security. Work can also be a source of stress, but when done properly can be a great way to make a living, develop skills, and better oneself.

Therefore, The variables that are not state functions are m (mass), q (heat), and w (work).

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Robert A. Millikan able to determine, either from his own work, The mass of an electron. Hence, the correct option is (c).

Robert A. Millikan was able to determine the charge of an electron, but the discovery of the electron itself was made by J.J. Thomson. Millikan's work built on Thomson's discovery and helped to refine our understanding of the properties of electrons. By conducting the oil drop experiment, Millikan was able to measure the charge of an electron with great precision. He observed the motion of tiny oil droplets that were suspended in an electric field, and by measuring the strength of the electric field and the speed of the droplets, he was able to calculate the charge of each droplet. By adjusting the strength of the electric field, he was able to find the smallest possible charge that a droplet could have, which corresponded to the charge of a single electron. However, Millikan did not determine the mass of an electron, as this was already known from Thomson's work on the charge-to-mass ratio of electrons. Additionally, Millikan did not propose a model of an atom with a small, positively charged nucleus, as this idea was developed later by Ernest Rutherford.

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If the modern penny has a mass of 2.500 g when it is manufactured, but it is mostly zinc metal. The number of  atoms of copper (Cu) that are in a modern penny is: 5.91 x 10^18 atoms of copper (Cu).

To calculate the number of atoms of copper (Cu) in a modern penny, we need to know the atomic mass of copper, which is 63.55 g/mol, and the Avogadro's number, which is 6.022 x 10^23 atoms/mol.

First, we'll calculate the number of moles of copper in the penny by dividing its mass by the atomic mass of copper:

0.0625 g / 63.55 g/mol = 9.84 x 10^-5 mol

Next, we'll multiply the number of moles by Avogadro's number to get the number of atoms:

9.84 x 10^-5 mol * 6.022 x 10^23 atoms/mol = 5.91 x 10^18 atoms

Therefore, there are approximately 5.91 x 10^18 atoms of copper (Cu) in a modern penny.

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