A chemist runs a reaction and has a percent yield of only 30%. Which of the following would NOT explain the low percent yield?



The reaction was stopped too soon, and some of the reactant had not yet been converted to product.

One of the products was a gas that was not contained and weighed.

The product still had moisture in it when the mass was recorded.

Some of the product was spilled before the mass was recorded.

Answer:

[tex]\rm ^{216}_{\phantom{2}84}Po \to ^{\phantom{-}0}_{-1}\beta + ^{216}_{\phantom{2}85}At[/tex].

Both mass number (A) and atomic number (Z) shall conserve. Hence the mass number of the daughter nuclide shall be 216 and its atomic number be 85.

Let the mass number of the daughter nuclide be [tex]A[/tex].

[tex]216 = 0 + A[/tex].

[tex]A = 216[/tex].

Let the atomic number of the daughter nuclide be [tex]Z[/tex].

[tex]84 = (-1) + Z[/tex].

[tex]Z = 85[/tex].

Look up the atomic number of the daughter nuclide in a modern periodic table. Alternatively, given that this reaction is a beta-minus decay, look for the element to the right of the parent nuclide.

Explanation:

Nuclides are made of neutrons and protons.

The mass number shall thus be greater than or equal to the atomic number of a nucleus. However, note that occasionally the atomic number of electrons (beta-minus particles) is written as -1. The atomic number of positrons (beta-plus particles, the antiparticle of electrons) is written as +1. Beta particles do not contain protons or neutrons and might not satisfy rule [tex]A \ge Z[/tex].

[tex]^{A}_{Z}\mathrm{X}[/tex].

By convention

Both mass number and atomic number shall conserve in nuclear reactions. In other words, the sum of all mass numbers on the left-hand side of a nuclear equation shall be the same as the sum of all mass numbers on the right-hand side. So is the case with atomic numbers. For this nuclear equation,

Mass number on the left-hand side:

Mass numbers on the right-hand side:

Mass numbers conserve. Therefore,

[tex]216 = 0 + A[/tex].

[tex]A = 216[/tex].

Similarly,

Atomic number on the left-hand side:

Atomic numbers on the right-hand side:

[tex]84 = (-1) + Z[/tex].

[tex]Z = 85[/tex].

Refer to a modern periodic table. What is the element with the atomic number [tex]Z = 85[/tex]? Astatine.

Alternatively, notice that the atomic number [tex]Z[/tex] has increased by [tex]1[/tex] relative to the parent nuclide [tex]\rm ^{216}_{\phantom{2}84}Po[/tex]. Elements on a modern periodic table are order in the increasing order of atomic numbers. As a result, the daughter nuclide shall be on the right of the parent element.

Complete the atomic symbol of the daughter nuclide:

[tex]\rm ^{216}_{\phantom{2}85}At[/tex].

Final answer:

The balanced nuclear equation for the decay of polonium-216 with an emission of a beta particle is: ^{216}Po_{84}
ightarrow 0_{-1}eta + ^{216}At_{85}. The daughter nuclide is astatine-216.

Explanation:

The student has asked to write a balanced nuclear reaction for the decay of polonium-216 (216Po) with an emission of a beta particle (0-1eta). The Law of Conservation of Matter dictates that the sum of the mass numbers (top numbers) and the atomic numbers (bottom numbers) must be the same on both sides of the reaction. This is a fundamental principle in balancing nuclear reactions, also known as nuclear accounting.

To find the daughter nuclide in the given decay reaction, we recognize that the emission of a beta particle (0-1eta) increases the atomic number by 1, but does not change the mass number. Thus, the daughter nuclide will have an atomic number of 85 and a mass number of 216. Since the periodic table is organized by atomic number, we can easily look up element 85 to find that it is astatine (At), making the daughter nuclide 216At.

The balanced nuclear equation is:

216Po84 ightarrow 0-1eta + 216At85

Answer:

It’s simple. You’re doing it right, the question is just messed up. If you think about it it’s like H2O

Explanation:

Answer:

The answer is C7H8N4O2.

Same problem as your other question - you rounded in a place where you shouldn't have (see explanation below, exact same process)!

Explanation:

These are percents by mass. Pretend you have a 100g sample. That means you have:

46.66g C

4.48g H

31.10g N

17.76g O

Divide each by molar mass to find the moles of each:

C: 46.66 / 12 = 3.89 mol

H: 4.48 / 1 = 4.48 mol

N: 31.10 / 14 = 2.22 mol

O: 17.76 / 16 = 1.11 mol

Now divide each of these values by the lowest of the three to find the ratio between each element in the compound:

C: 3.89 / 1.11 ≈ 3.5

H: 4.48 / 1.11 ≈ 4

N: 2.22 / 1.11 = 2

O: 1.11 / 1.11 = 1

As with your other question, 3.5 is too different from 3, so you can't round it down. The .5 makes it easy to find the LCD - it's 2. Multiply each of the numbers by 2 to get your final answer:

C: 3.5 x 2 = 7

H: 4 x 2 = 8

N: 2 x 2 = 4

O: 1 x 2 = 2

Again, if you were to take the percent masses of the empirical formula you came up with, you'll see they're quite different from the one the question provided, which is why you can't round in this situation.

Answer:

NH₄NO₃.

Explanation:

HNO₃ + NH₄OH → NH₄NO₃ + H₂O.

It is clear that it is an acidic salt.

So, its pH is < 7.

Answer:

Red Giant

Explanation:

The stage in which a typical star has completely stopped fusion is called the  Red Giant.

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Final answer:

A star stops fusion at the end of its lifecycle, becoming a white dwarf. Fusion of iron in the core requires energy, leading to the star's demise. Eventually, the white dwarf may explode as a type Ia supernova.

Explanation:

The stage in which a typical star has completely stopped nuclear fusion marks the end of its life cycle. After a star consumes all its hydrogen and goes through subsequent stages fusing heavier elements, it eventually reaches a point where further fusion is not energetically favorable. For example, the fusion of iron actually requires energy, signaling a catastrophic end for any star that reaches this stage.

A typical example of such an end state is when a star becomes a white dwarf. This occurs when all nuclear fusion has ceased within the star's interior, and it's stabilized by degeneracy pressure. The white dwarf represents the cooling cinder of a once vibrant star. Despite a brief resurgence of fusion in its outer layers that consume any remaining hydrogen, the star has effectively 'died' in terms of its stellar lifecycle. Over time, it may succumb to a violent end and be destroyed by a type Ia supernova, especially if it accumulates additional material from a companion star.

Answer:

Amount of oxygen = 2 * 5.43 moles

                             = 10.86 moles

Explanation:

Answer:Correct answer 10.9

Explanation:

Answer:

the scattering and reflection of light by dust particles

Answer:

the scattering and reflection of light by dust particles

Explanation:

The process of scattering is responsible for the different colors we see in the sky.

Different colors have have some different wavelengths, and hence, scatter accordingly.

The small dust particles that is present in the air , gets scattered as the light falls on the dust particles , and hence give various colors to the sky , since , blue is the color that is scattered the most , therefore , maximum sky is blue in color .

Similarly during night time , there is no light , hence , the sky appears dark.

Answer:

The answer is B (sodium is more reactive)

Explanation:

The lesser reactive element to magnesium is present on the left side of the magnesium in the periodic table in the same row. Thus, option B is correct.

The periodic table is given as the arrangement of the elements in columns and rows based on the increasing order of the atomic number and the number of valence electrons.

In a periodic table, on moving from left to right reactivity increases, and from top to bottom reactivity decreases.

Thus, the element with the lesser reactivity than magnesium is present in the left of the magnesium in the same row. Thus, option B is correct.

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Answer:

Explanation:

5 g Mg     1 mole Mg

            * ___________ =  0.208333 moles Mg

               24 grams Mg

24 is from the periodic table

Answer:

I want to say B but I'm not sure

Answer:

The statement E is true on average kinetic energy; and mass and temperature.  If gases from different types have same quantity of mass and same quantity of temperature then there will be same quantity in average kinetic energy.

Explanation:

The gaseous kinetic theory has the assumption that the size of molecules in any compound is very small compared to the distance between them. Also, the molecules are always in a vibration and it collides with boundary of cylinder and with each other.

In reference to the kinetic theory of gases, the different gases having different mass at same temperature always have the same quantity of average kinetic energy because the average kinetic energy of gases has directly proportional relation to the gaseous temperature.

The gas at higher temperature has higher kinetic energy amount and vice-versa.

independent variable is temperature and dependent is the number of cold drinks sold. It's because the temperature is being changed without any outer influence while the number of cold drinks sold changes based on the weather. It's like cold drinks are going to sell better in the summer because it's hot vs in the winter because it's cold. The change in temperature isn't relying on anything but the drink is.

Answer:

your answer to your question is B

I think answer of this question is D

Answer:

C

Explanation:

same electron configuration

Explanation:

Every gas molecules are held by weak Vander waal forces because of which each molecule of a gas is free is move from one place to another.

This causes more number of collisions between molecules of a gas and gaps will also increase between each molecule.

As a result, gases are able to diffuse or spread at a faster rate.

Hence, generally it is true about the particles in a gas that gases diffuse at a faster rate.

Answer:

C12H12NO3

Explanation:

Answer:

The answer is C8H8O3.

You rounded in a place where you shouldn't have (see explanation below)!

Explanation:

These are percents by mass. Pretend you have a 100g sample. That means you have:

63.15g C

5.30g H

31.55g O

Divide each by molar mass to find the moles of each:

C: 63.15 / 12 = 5.26 mol

H: 5.30 / 1 = 5.30 mol

O: 31.55 / 16 = 1.97 mol

Now divide each of these values by the lowest of the three to find the ratio between each element in the compound:

C: 5.26 / 1.97 ≈ 2.67

H: 5.30 / 1.97 ≈ 2.69

O: 1.97 / 1.97 = 1

These aren't whole numbers and you can't just round up. If the numbers you ended with were something around 2.98, I would be fine with rounding to 3. But here 2.67 is too different from 3 to the point where we're actually considering a completely different compound.

So, we need to multiply them all by some factor to get whole numbers that will make sense in a chemical formula. If you express 2.67 and 2.69 as fractions, you get about 8/3, and 1 can be represented as 3/3, so 3 is the LCD of all three numbers. Multiply each of the numbers by 3 to get your final answer:

C: 2.67 x 3 ≈ 8

H: 2.69 x 3 ≈ 8

O: 1 x 3 = 3

Side note: if you take the percent masses of the empirical formula you came up with, you'll see they're quite different from the one the question provided, which is why you can't round in this situation:

Finding mass using your empirical formula:

C: 3 x 12 = 36

H: 3 x 1 = 3

O: 1 x 16 = 16

Total mass = 36 + 3 + 16 = 55

% mass:

C: 36/55 = 65.45% (vs. 63.15%)

H: 3/55 = 5.45% (vs. 5.30%)

O: 16/55 = 29.09% (vs. 31.55%)

The values differ by more than 2% in some cases!

Answer:

the 3rd option for make sense,so that's out

Dalton was the pioneer behind the atomic model,but he certainly didn't believe in the nucleus or electrons,much lest electron shells.

Chadwick's discovery was the discovery of the neutron,not electron energy levels.

Niels Bohr's model was an attempt at explaining the hydrogen atom's spectrogram,followed by Erwin Schrödinger.Thus the first option is the answer

Niels Bohr's model of the atom, which posits electrons in fixed energy levels, was supported by observations of the hydrogen atomic spectrum. This spectrum showed distinct lines corresponding to electron transitions, which corroborated Bohr's theory that electrons occupy specific allowed orbits.

Niels Bohr, a Danish physicist, introduced a groundbreaking model of the atom in 1913. Central to Bohr's model was the concept that electrons move in definite orbital paths around the nucleus with specific allowable energy levels, which he referred to as stationary states. This idea was demonstrated using the hydrogen atomic spectrum as evidence, where the emitted light could be seen as distinct lines, each corresponding to an electron moving between these fixed energy levels.

In Bohr's theory, each energy level is quantized, meaning electrons can only occupy certain regions of space at certain energy levels. The electron can jump from one energy level to another, but it does not emit or absorb energy while staying in a given energy level. The hydrogen atomic spectrum provides a visual representation of these jumps as unique spectral lines created when electrons move back to lower energy levels, releasing energy in the form of light.

Bohr's conclusions were primarily derived from observations of the hydrogen atomic spectrum. Hence, option A, Hydrogen atomic spectrum, is the strong support for Bohr's belief that electrons occupied different energy levels. His model successfully predicted the energy levels for hydrogen, earning him the Nobel Prize in Physics in 1922. However, this model could not fully explain the spectra of atoms with more than one electron.

That would be a description of a solid if that’s what your looking for. If not ask me in the comments:)

Particles vibrate in a rigid structure and do not move relative to their neighbours. It is the property of solid.

A solid is a state of matter that retains its shape and density when not confined.

Properties of solids: Solids have definite volume and shape.

Hence, particles vibrate in a rigid structure and do not move relative to their neighbours.

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Answer:

B. 2358.1

Explanation:

142×16.5=2343

ans+15.11=2358.2

Answer: A. 2,358

Look at the image below.

This is a significant figures calculator.

Answer: i belive its 55

Explanation:tyy

Answer:

The correct answer is D :Linear

Explanation:

Talking about molecular geometry and arrangement of atoms, liner geometry and trigonal bipyramidal arrangement of atoms would have 3 lone pairs and 2 no. of bond pairs.

For example, in ICl2 and XeF2, the central molecule has 3 lone pairs, and it shows sp3d hybridization.

In trigonal bipyramidal arrangement, orbitals have trigonal bipyramidal structure. It has three-atom molecules which have a linear shape and the orbitals on the equator contain three lone pairs each.

Answer:

linear

Explanation:

a p e x

Answer:

The substance that dissolves

Explanation:

Solute is the substance that disappears into a liquid. For example,when salt dissolves in water,the salt is the solute because it is the substance that saluted.

Answer:

What is a solute?

The answer is C. The substance that gets dissolved.

What is a solvent?

The answer is C. The substance

that dissolves the solute.

Explanation:

These are two questions and two answers

Question 1.) The atomic emission spectrum of hydrogen includes four visible colors of light: red, blue-green, indigo, and violet. Which color of light corresponds with the largest electron transition?

A.) blue-green

B.) red

c.) indigo

d.) violet

Answer:

Explanation:

The atomic emission spectrum is the set of coloer lines or frequencies of electromagnetic waves emitted by the atoms of an element due to the transition of the electrons from an upper energy level to a lower energy level.

The higher the jump of the electron during the transition,  the higher the energy of th emssion and the higher the frequency of the electromagnetic wave emitted.

The color of light is related with the frequency of the electromagnetic wave.

The order of the frequencies for the visible light are:

Then, violet is the visible light with the highest energy, whicn means that it corresponds to the largest electron transition.

Quesiton 2.) Hydrogen’s emission spectrum includes a line of violet light that has a frequency of 7.31∗10¹⁴ Hz. What is the energy (in joules) a photon of the violet light?

Answer:

Explanation:

The energy of a photon of light is related with its frequency by the Planck - Einstein equation:

Where,

Then, you can just substitute the frequency and the constant to obtain the energy:

(1) The color of light that corresponds with the largest electron transition is violet.

(2) The energy of the violet light with the given frequency is 4.84 x 10⁻¹⁹ J.

The increasing order of the frequencies of the visible light in electromagnetic spectrum include the following:

Thus, the color of light that corresponds with the largest electron transition is violet.

(2)

The energy of the violet light with the given frequency is calculated as follows;

E = hf

where;

E = (6.626 x 10⁻³⁴) x (7.31 x 10¹⁴)

E = 4.84 x 10⁻¹⁹ J.

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Answer:

Table salt dissolving in water

Explanation:

NaCl(s) ⟶ Na⁺(aq) + Cl⁻(aq)

Sodium chloride is an ionic solid. When it goes into solution, the ions separate from the surface of the solid. The process is called dissociation.

A is wrong. In the solution process, the molecules simply separate from the surface of the crystal.

C is wrong. When HCl dissolves in water, it forms hydronium and chloride ions. The dissolution of covalent compounds in water to produce ions is called ionization.

D is wrong. Vegetable oil does not dissolve in water.

Answer:

The first blank is half

The second blank is replicated

Explanation:

Cells produced at the end of telophase I have half as many replicated chromosomes as cells that started the process.

Answer:

increases

Explanation:

The barometer is a device that uses mercury in order to work and be able to measure the air pressure. The mercury reacts to the air pressure, so it either goes up or down. If the mercury goes down, that means that it is pressed more, thus the air pressure has increased, or rather is higher. If the mercury is lifting up, that means that there is less pressure from the air, thus the air pressure has declined, or rather is lower. It is a simple device that manages to do a very important job, and it is one of the most important devices used by the meteorologists for telling the current weather conditions, as well as predicting them for the next few days.

Answer:

the answer would be B.20n-->X<--20n

Explanation:

the amount of force is equal and balances out each other forming an equilibrium

Answer:

This solution is likely to be basic.

Assumption: this solution is under room temperature, where [tex]K_w = 10^{-14}[/tex].

Explanation:

The concentration of hydronium ions [tex]\mathrm{H_3O^{+}}[/tex] in the solution can be found from the [tex]\mathrm{pH}[/tex] value. This relationship does not depends on temperature.

[tex]\mathrm{[H_3O^{+}]} = 10^{-\mathrm{pH}} = 10^{-8.55}[/tex].

The question states that for this solution, [tex]\rm [H_3O^{+}] = 8.55\;M[/tex]. Apply the relationship between [tex]\mathrm{[H_3O^{+}]}[/tex], [tex]\mathrm{[OH^{-}]}[/tex], and [tex]K_w[/tex]. Note that the value of [tex]K_w[/tex] is dependent on the temperature of the solution.

[tex]\displaystyle \rm [OH^{-}] = \frac{\mathnormal{K_w}}{[H_3O^{+}]} = \frac{10^{-14}}{10^{-8.55}} = 10^{-5.45}\; M[/tex].

In other words,

[tex]\rm [H_3O^{+}] < [OH^{-}][/tex].

In other words, this solution is basic.

Answer:

N=+2

O=-2

Explanation:

The compound NO is electrically neutral.

Lets assign the oxidation number of nitrogen to be N. The oxidation number of oxygen (-2) is then used as a reference.

For the compound to have a zero charge,  sum of the oxidation numbers equals zero.

N+ (-2)=0

N=+2

O=-2

Answer:

108.3g

Explanation:

Given parameters:

Volume of solution = 570mm = 0.57L (1000mm = 1L)

Molarity of solution = 2M

Unknown

Mass of MgCl₂

Solution

We first find the  number of moles in the given concentration of magnessium chloride using the expression below:

       Number of moles of MgCl₂= Molarity x volume = 2 x 0.57 = 1.14moles

Using this known moles, we can the unknown mass of MgCl₂ the technician would require:

       Mass of MgCl₂ required = number of moles of MgCl₂ x molar mass

Molar mass of MgCl₂:

Atomic mass of Cl = 35.5g

Atomic mass of Mg = 24g

MgCl₂ = 24 + (35.5x2) = 95gmol⁻¹

Mass of MgCl₂ required = 1.14mole x 95gmole⁻¹ = 108.3g

The required mass is 109 grams.

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Answer:

0.75g

Explanation:

From the given problem, the known parameters are:

Number of mole of BeO = 0.03mole

The unknown is the mass of BeO = ?

The formula of the compound is BeO

To solve this kind of problem, we use the mole relationship between number of mole and mass. This is expressed below mathematically:

          Mass of BeO = number of moles of BeO x Molar mass of BeO

The molar mass of BeO:

Atomic mass of Be = 9g

Atomic mass of O = 16g

Molar mass of BeO = 9 + 16 = 25g/mol

Mass of BeO = 0.03 x 25 = 0.75g

The mass of BeO that participates is 0.75g

The mass of Beryllium oxide that participates in the chemical reaction is 0.7506 grams.

To calculate the mass of Beryllium oxide that participates in the chemical reaction, we need to convert the given amount of moles to grams. The molar mass of Beryllium oxide (BeO) is 25.02 g/mol. Since we know that 0.0300 moles of BeO participate in the reaction, we can use the formula:

Mass = moles × molar mass

Mass = 0.0300 mol × 25.02 g/mol = 0.7506 g

Therefore, the mass of Beryllium oxide that participates in the chemical reaction is 0.7506 grams.

Answer:

Bent.

Explanation:

A molecule with two bound groups and two lone pairs have a bent shape.

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Answer:

bent

Explanation: