Does acetylene, C2H2 have a linear shape and the bond angle of 180º?

Francium has the largest atomic radius due to having the highest number of energy levels and the least nuclear pull.

The correct answer is B. Francium has the largest atomic radius because it has the highest number of energy levels and the least nuclear pull. The atomic radius refers to the size of an atom, which is determined by the distance between the nucleus and the outermost electron shell.

Francium has the highest number of energy levels, which means the electrons are located farther from the nucleus, resulting in a larger atomic radius. Additionally, francium has the least nuclear pull, meaning the positive charge of the nucleus has less of an attraction on the outermost electrons, allowing them to spread out more.

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To find the mass of 5 moles of Fe₂O₃, multiply its molar mass (159.70 g/mol) by 5, resulting in 798.5 grams. This calculation uses the molar mass of the elements iron and oxygen.

To find the mass of 5 moles of Fe₂O₃, we need to use the molar mass of the compound. Fe₂O₃ has the following molar mass:

Fe: 55.85 g/mol

O: 16.00 g/mol

Since there are 2 iron atoms and 3 oxygen atoms in Fe₂O₃, the calculation is:

2 × 55.85 g/mol + 3 × 16.00 g/mol = 159.70 g/mol

Now, multiply the molar mass by the number of moles:

159.70 g/mol × 5 mol = 798.5 g

Therefore, the mass of 5 moles of Fe₂O₃ is 798.5 grams.

Yes, it is possible to visually detect the presence of potassium, even though sodium produces a brighter and more persistent color.

In a flame test experiment, the color observed in the flame is due to the excitation and subsequent relaxation of electrons in atoms or ions.

Each element has a unique set of energy levels, and when the electrons transition between these levels, they emit light of specific wavelengths, which we perceive as colors.

To enhance the visibility of potassium's flame color, one could adjust the experimental conditions, such as using a higher concentration of potassium or reducing the concentration of sodium.

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Final answer:

Potassium can be detected in the presence of sodium during a flame test by looking for its characteristic lilac color. Special equipment like spectrometers can enhance the detection of potassium's color in the flame test.

Explanation:

In a flame test experiment, when sodium is present, it can overwhelm other colors due to its bright yellow flame, which is highly persistent and intense. However, potassium can still be detected visually in the presence of sodium in a flame test. Potassium imparts a lilac color to the flame, which can be observed at the moment when the sodium's yellow emission fades, or by observing the edge of the flame where the color may be less intense. Additionally, the use of spectrometers or filters can help in better visualizing the potassium flame in the presence of sodium.

Answer: Option (a) is the correct answer.

Explanation:

Conductivity of a solution depends number of ions present in the solution. As these ions move from one place to another and thus there will be easily flow of current.

So, when there is increase in concentration then it means there are moer number of ions present into the solution.

Thus, conductivity will also increase due to increase in concentration of salt solution.

The two species diverged from a common ancestor approximately 40 million years ago, calculated by multiplying the total number of mutations (eight) by the mutation rate (one mutation per 5 million years).

To estimate the time two species shared a common ancestor using a molecular clock, one must know the mutation rate and the number of mutations that have accumulated in both species since they diverged from a common ancestor. In the given problem, the molecule has a neutral mutation rate of one mutation per 5 million years. If the molecules in the two species differ by a total of eight mutations, the time since the common ancestor can be estimated by multiplying the number of mutations by the rate of mutation. Therefore, 8 mutations  imes 5 million years per mutation equals 40 million years ago.

The kinetic theory of matter states that all particles of matter are in constant motion.

The following are the postulates of kinetic theory of gases:

1. The particles of gases are in constant and random motion. Due to this motion, they collide with each other and walls of the container.

2. The particles of gases have point mass and zero volume.

3. The particles of gases have no such attraction or repulsion between them.

4. The kinetic energy with which the particles are moving is directly proportional to temperature. A temperature increases, kinetic energy also increases, and particles collide each other more frequently.

5. The particle of gases at given temperature have same kinetic energy.

Answer : The resulting solution will have a pH of 7.

Explanation:

Whenever acid and base reacts with each other to form water molecule is called Neutralization reaction. This water molecules is formed from the  hydronium ion ([tex]H^+[/tex]) from acid and hydroxide ion([tex]OH^-[/tex]) from base.

When the equal volumes of acid and base of equal strength are combined, the resulting pH of the solution becomes 7.

The pH 7 value means that the solution is neutral.

A- There was no apparent source for the uranium salts' energy (just took the edg test)

Answer:

The correct answer is "There was no apparent source for the uranium salts’ energy."

Explanation:

Becquerel while working on X-rays accidentally discovered radioactivity. While working with uranium salts he observed that it emitted penetrating radiation that exposed photographic film. His contemporaries did not know radioactivity and hence they believed that there was no apparent source for the uranium salts’ energy.

Answer:

Above is correct, but the heat of reaction is 176.18 J/mol

Explanation:

Answer:

1) Electrons get farther from the nucleus.

2) a cation that has a smaller radius than the atom.

Explanation:

1) ionization energy is the energy required to remove the valence electron from an isolated gaseous atom of an element.

Thus it requires some energy to remove the electron as electrons are attracted towards nucleus (positive protons are present) due to nuclear charge.

As the size increases on moving top to bottom (due to more number of shells) the distance of electrons from the nucleus increases which decreases the effective nuclear charge on electrons, decreasing the ionization energy.

2) When an atom loses an electron it attains a positive charge and is known as cation.

A cation has smaller size than the neutral atom as the less electrons are attracted towards nucleus and thus feel more effective nuclear charge.

The answers are 1. The ionization energy tends to decrease from the top to the bottom of a group because D. Electrons get farther from the nucleus. 3. When electrons are removed from the outermost shell of a calcium atom, the atom becomes D. a cation that has a smaller radius than the atom.

The correct answer for question 1 is D. Electrons get farther from the nucleus  best explains why ionization energy tends to decrease from the top to the bottom of a group

Ionization energy is the energy required to remove an electron from an atom in the gaseous state. As one moves down a group in the periodic table, the ionization energy tends to decrease. This is because each element down the group has an additional shell of electrons. The outermost electrons are farther from the nucleus, which means they experience a weaker effective nuclear charge. The increased distance from the nucleus and the screening effect of the inner electrons make it easier to remove an outer electron, thus decreasing the ionization energy.

The incorrect options can be explained as follows:

A. The number of orbitals increases, not decreases, as one moves down a group, which actually contributes to the decrease in ionization energy.

B. The number of neutrons generally increases as one moves down a group, but this does not directly affect the ionization energy.

C. Electrons do not get closer to the nucleus; in fact, they get farther away as additional electron shells are added, which is why the ionization energy decreases.

The correct answer for question 3 is D. a cation that has a smaller radius than the atom.

When electrons are removed from an atom, the atom becomes a cation (a positively charged ion). In the case of calcium, which has two electrons in its outermost shell, removing these electrons results in a Ca^2+ ion. Because the outermost electrons are no longer there to shield the nuclear charge, the remaining electrons are more strongly attracted to the nucleus. This causes the ion to have a smaller radius than the neutral atom.

The incorrect options can be explained as follows:

A. An anion is formed when an atom gains electrons, not when electrons are removed.

B. An anion would have a larger radius than the neutral atom because the added electrons increase repulsion and decrease the effective nuclear charge.

C. A cation has a smaller radius than the neutral atom, not a larger one, because the loss of electrons increases the effective nuclear charge, pulling the remaining electrons closer to the nucleus."

Final answer:

Helium is used in balloons because it is lighter than air and safely floats due to its low density and nonreactive, nonflammable properties. So the correct option is b.

Explanation:

Helium is used in balloons because it is lighter than air. This is due to helium's much lower density and atomic mass compared to the average molar mass of air. Helium's atomic mass is approximately 4.00 g/mol, while air has an average molar mass of about 29 g/mol. Hence, when a balloon is filled with helium, it floats. Another critical property of helium that makes it the gas of choice for balloons is its nonreactivity. Helium is chemically non-reactive and nonflammable, which contrasts with hydrogen, another light gas that is, however, highly flammable. This property of helium makes it safe for use in various applications like balloons, airships, and blimps. Furthermore, in environments where there is a high risk of fire or explosion, such as in welding, helium serves as an inert protective atmosphere. Finally, for deep-sea divers who operate under high pressure, a mixture of oxygen and helium is essential to avoid nitrogen narcosis, commonly known as the “rapture of the deep”.

Explanation:

Photoelectric effect: Electrons are ejected out from the surface of metal when light of sufficient frequency falls upon shiny surface of metals. light is made up small bundles of energy packets named photons which when falls on surface transfer their energy to electrons due which electrons ejects out of the metallic surface. The energy for one photon was given by expression:

E=h[tex]\nu[/tex], or [tex]E\propto \nu[/tex]

h=Planck's constant, [tex]\nu[/tex]= frequency of the light

Kumar can increase the energy of emitted electron by using light with higher value of frequency than the frequency of red light. This is because the energy  carried by the photon of a light is directly proportional to the frequency of the light. Higher the value of frequency of light higher will be the value of energy of a photon. And photon with higher energy will impart more amount of energy to an electron while ejection.

Avogadro's number is the number of units (atoms, molecules) in 1 mole of substance:

Answer:

165Kcal in a cup of whole milk

Explanation:

Hello! Let's solve this!

We know that 1g

carbohydrate = 4 Kcal

1g protein = 4Kcal

1g fat = 9Kcal

We do the conversion of each one

carbohydrates = 12g * 4Kcal * g = 48Kcal

Proteins = 9g * 4Kcal / g = 36Kcal

fat = 9g * 9Kcal / g = 81Kcal

We add all the results to have the total Kcal

48Kcal + 36Kcal + 81Kcal = 165Kcal in a cup of whole milk

Answer:

Fluorine (F) would be least likely to form a cation

Explanation:

A cation is a positively charged atom (or molecule) which has lost electron (or electrons). Electropositive elements show a greater propensity to lose electrons and form cations. These are usually metals that are present on the left of the periodic table.

Electropositivity or the tendency to lose electrons and form cations increases on going down a group and decreases across a period. In the given examples:

Potassium, K is an alkali metal and will lose electrons readily to form a cation

Nitrogen (N), Fluorine (F) and chlorine (Cl) are all non metals which prefer to accept electrons and form anions instead. Among the three, F is the most electronegative i.e. it will prefer to accept electrons and form F- rather than F+.

Answer:

[tex]\huge \boxed{\mathrm{2}}[/tex]

[tex]\rule[225]{225}{2}[/tex]

Explanation:

[tex]\sf CH_4+ O_2 \Rightarrow CO_2 + H_2O[/tex]

Balancing the Hydrogen atoms on the right side,

[tex]\sf CH_4+ O_2 \Rightarrow CO_2 +2 H_2O[/tex]

Balancing the Oxygen atoms on the left side,

[tex]\sf CH_4+ 2O_2 \Rightarrow CO_2 +2 H_2O[/tex]

[tex]\rule[225]{225}{2}[/tex]

A dilute, aqueous potassium nitrate solution is classified as a homogeneous mixture, as it is a uniform mixture of solute and solvent at the molecular level.

A dilute, aqueous potassium nitrate solution is best classified as a (2) homogeneous mixture, also known as a solution. This classification is due to the fact that potassium nitrate is a highly soluble ionic compound that, when dissolved in water, dissociates into ions, creating a mixture with a composition that is uniform throughout. Therefore, it is not possible to distinguish between the different components of the mixture, even with a powerful microscope. If we were talking about potassium hydroxide, it would similarly be fully soluble and dissociate completely, yielding a specified concentration of hydroxide ions in the case given. Nevertheless, for potassium nitrate, the dissolution would result in potassium and nitrate ions evenly distributed in the solution.

Answer:

0.014 M/s

Explanation:

The rate of a reaction depends on the concentration of a particular compound and it stoichmetry coefficient. For the reaction:

aA + bB → cC +dD

The rate can be calculated:

r = -(1/a)xΔ[A]/Δt = -(1/b)xΔ[B]/Δt = (1/c)xΔ[C]/Δt = (1/d)xΔD/Δt

The minus signal for the reagents its because they are being consumed, so Δ[A] and Δ[B] will be negative, and r must be positive. Δt is the time variation.

So, for the reaction given, in t = 0, [A] =1 M, and in t= 10s, [A] = 0.86 M, then

Δ[A] = -0.14 M

r = -(Δ[A]/Δt)

r = -(-0.14/10)

r = 0.014 M/s

Final answer:

Milk of magnesia is a base with a pH greater than 7, specifically around 10.5, making it effective as an antacid. It contrasts with neutral substances, like water, and acidic substances, like wine.

Explanation:

Milk of magnesia is a base. This determination is based on its pH level, which is greater than 7. Specifically, milk of magnesia, which is largely comprised of magnesium hydroxide (Mg(OH)2), has a pH of approximately 10.5. This high pH level classifies it as a basic substance, meaning it has properties that counteract acids. This characteristic is why milk of magnesia is commonly used as an antacid to neutralize stomach acid and alleviate symptoms of indigestion and heartburn.

In comparison, substances with a pH of 7, such as pure water, are considered neutral, neither acidic nor basic. Substances like wine, with a pH less than 7, are classified as acidic. Understanding the pH scale and the properties of acids and bases is essential in chemistry and various practical applications, including medicine and nutrition.

Answer

Explanation

Final answer:

To find the moles of carbon in the original unknown compound, we use the mass of the carbon dioxide produced from combustion, and divide by its molar mass. This gives us the moles of carbon dioxide, which are equivalent to the moles of carbon in the sample, resulting in 0.0834 mol of carbon.

Explanation:

To determine how many moles of carbon, C, were in the original 2.50g sample of an unknown compound after combustion, we need to use the mass of carbon dioxide (CO2) produced. Every mole of CO2 contains one mole of C, so the moles of C are equal to the moles of CO2.

First, calculate the moles of CO2 using its molar mass:
Moles of CO2 = mass of CO2 / molar mass of CO2
Molar mass of CO2 is approximately 44.01 g/mol
Moles of CO2 = 3.67 g / 44.01 g/mol = 0.0834 mol

Since each mole of CO2 represents one mole of carbon, the moles of carbon in the original compound is also 0.0834 mol.