Please help anyone??

Answer:

he universe's average temperature and rate of expansion support the idea that it began as one super-dense and hot mass 13.8 billion years ago.

Ocean tides are caused by the uneven gravitational pulls of the Moon and Sun on different parts of Earth.

Explanation:

These statements are objective truths or rational speculations adequately supported by evidence.  The others are from unreliable sources, and are based on opinion.

the answer is A!

Answer:

A and C are correct, I took the test

Explanation:

There could be several reasons why the crystallization failed. One possibility is that the impurities in the sulfanilamide prevented the formation of crystals.

Another possibility is that the solution was not cooled slowly or sufficiently, which could prevent the formation of crystals.

Another reason why the crystallization might have failed is due to the solvent choice. Ethyl alcohol might not be the best solvent for sulfanilamide, and a different solvent might be needed to achieve the desired crystal formation. Additionally, the temperature of the solution may not have been low enough, or it may not have been cooled slowly enough for the crystals to form.

To make the crystallization work, a seed crystal can be added to the solution. A seed crystal is a small crystal of the same substance that is added to the solution to promote crystal growth. The seed crystal provides a surface for the molecules in the solution to attach to and align with, which can encourage the formation of additional crystals. The seed crystal can be added by touching it to the bottom of the container or by dropping it into the solution. Alternatively, the solution can be left to cool for a longer period of time, or it can be seeded and then left to cool slowly.

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Answer:

Vanadium (23)

Explanation:

You can add all the small numbers up and then from that total look at a periodic table and find the element that has that atomic mass.

The total is 23, if you look at the chart the element with an atomic mass of 23 is Vanadium.

In the reaction, A+ 3B -- > 2C + D the reaction is first order with respect to reactant A and second order with respect to reactant B. If the concentration of A is doubled and the concentration of B is halved, the rate of the reaction would be zero order by a factor of 1/2

The reaction given in the question is -

2A  + 3 B ---->  2C + D

From , the above reaction the rate law is written as -

rate = k [ A ]²[ B ]³

where ,

k = rate constant

In the above equation the order is determined by the sum of the powers of the concentrations , i.e. 2 + 3 = 5 order , which never possible ,

Hence , in the question ,

The by changing the concentration of B , the rate does not change .

hence , the rate is independent of the concentration of B .

Therefore ,

The order with respect to B will be zero .

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Q1. The formula for the energy levels of hydrogen is E = -13.6 eV/n².

Q2. a) The wavelength for the transition between n=1 and n=6 is approximately 93.5 nm. b) The wavelength for the transition between n=25 and n=26 is approximately 29.46 nm.

Q3. For the transitions in Q2, the relative densities are approximately 0.73 and 0.995, respectively.

Q4. The Lambert-Beers law relates the intensity of light transmitted through an absorber to the absorber's density, cross section for absorption, and position within the medium. It is expressed as I(x) = I₀ * exp(-n * σ(λ) * x).

Q1. The formula for the energy levels of hydrogen is given by the Rydberg formula, which is used to calculate the energy of an electron in the hydrogen atom:

E = -13.6 eV/n²

Where:

- E is the energy of the electron in electron volts (eV).

- n is the principal quantum number, which represents the energy level or shell of the electron.

Q2. a) To find the wavelength (in nm) for a transition between n=1 and n=6 in hydrogen, we can use the Balmer series formula:

1/λ = R_H * (1/n₁² - 1/n₂²)

Where:

- λ is the wavelength of the photon emitted or absorbed in meters (m).

- R_H is the Rydberg constant for hydrogen, approximately 1.097 x 10⁷ m⁻¹.

- n₁ and n₂ are the initial and final energy levels, respectively.

Plugging in the values, we have:

1/λ = (1.097 x 10⁷ m⁻¹) * (1/1² - 1/6²)

1/λ = (1.097 x 10⁷ m⁻¹) * (1 - 1/36)

1/λ = (1.097 x 10⁷ m⁻¹) * (35/36)

1/λ = 1.069 x 10⁷ m⁻¹

λ = 9.35 x 10⁻⁸ m = 93.5 nm

Therefore, the wavelength for the transition between n=1 and n=6 in hydrogen is approximately 93.5 nm.

b) Similarly, to find the wavelength (in nm) for a transition between n=25 and n=26 in hydrogen, we can use the same formula:

1/λ = R_H * (1/n₁² - 1/n₂²)

Plugging in the values:

1/λ = (1.097 x 10⁷ m⁻¹) * (1/25² - 1/26²)

1/λ = (1.097 x 10⁷ m⁻¹) * (1/625 - 1/676)

1/λ = (1.097 x 10⁷ m⁻¹) * (51/164000)

1/λ = 3.396 x 10⁴ m⁻¹

λ = 2.946 x 10⁻⁵ m = 29.46 nm

Therefore, the wavelength for the transition between n=25 and n=26 in hydrogen is approximately 29.46 nm.

Q3. To determine the relative density for each of the transitions in Q2, we need to calculate the ratio of the photon flux between the two states. The relative density is given by the equation:

Relative Density = (I(x2) / I(x1))

Where I(x2) and I(x1) are the photon fluxes at positions x2 and x1, respectively.

For a gas temperature of 300K, the relative density is proportional to the Boltzmann distribution of states, which is given by:

Relative Density = exp(-ΔE/kT)

Where ΔE is the energy difference between the two states, k is the Boltzmann constant (approximately 1.38 x 10⁻²³ J/K), and T is the temperature in Kelvin.

a) For the transition between n=1 and n=6, the energy difference is:

ΔE = E₁ - E₂ = (-13.6 eV / 1²) - (-13.6 eV / 6²)

ΔE = -13.6 eV + 0.6 eV = -13.0 eV

Converting the energy difference to joules:

ΔE = -13.0 eV * 1.6 x 10⁻¹⁹ J/eV = -2.08 x 10⁻¹⁸ J

Substituting the values into the relative density equation:

Relative Density = exp(-(-2.08 x 10⁻¹⁸ J) / (1.38 x 10⁻²³ J/K * 300 K))

Relative Density ≈ 0.73

Therefore, for the transition between n=1 and n=6, the relative density is approximately 0.73.

b) For the transition between n=25 and n=26, the energy difference is:

ΔE = E₁ - E₂ = (-13.6 eV / 25²) - (-13.6 eV / 26²)

ΔE ≈ -13.6 eV + 0.0585 eV ≈ -13.5415 eV

Converting the energy difference to joules:

ΔE ≈ -13.5415 eV * 1.6 x 10⁻¹⁹ J/eV ≈ -2.1664 x 10⁻¹⁸ J

Substituting the values into the relative density equation:

Relative Density = exp(-(-2.1664 x 10⁻¹⁸ J) / (1.38 x 10⁻²³ J/K * 300 K))

Relative Density ≈ 0.995

Therefore, for the transition between n=25 and n=26, the relative density is approximately 0.995.

Q4. Derivation of the Lambert-Beers law:

To derive the Lambert-Beers law, we consider a thin slice of the absorber with thickness dx. The intensity of light passing through this slice decreases due to absorption.

The change in intensity, dI, within the slice can be expressed as the product of the intensity at that position, I(x), and the fraction of light absorbed within the slice, nσ(λ)dx:

dI = -I(x) * nσ(λ)dx

The negative sign indicates the decrease in intensity due to absorption.

Integrating this equation from x = 0 to x = x (the total thickness of the absorber), we have:

∫[0,x] dI = -∫[0,x] I(x) * nσ(λ)dx

The left-hand side represents the total change in intensity, which is equal to I₀ - I(x) since the initial intensity is I₀.

∫[0,x] dI = I₀ - I(x)

Substituting this into the equation:

I₀ - I(x) = -∫[0,x] I(x) * nσ(λ)dx

Rearranging the equation:

I(x) = I₀ * exp(-nσ(λ)x)

This is the Lambert-Beers law, which shows the exponential decrease in intensity (photon flux) as light passes through an absorber. The law quantifies the dependence of intensity on the density of the absorber, the absorption cross section, and the position within the absorber.

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To solve this problem we are going to assume that the temperature at which the gold is found is room temperature.

We are going to use a property of materials that relates mass to volume, this is density. At this temperature, the density of gold is 19.3g/mL, the equation of density is:

We will use the following conversion factors:

1mL=1000mm^3

1atom=3.271x10^-22g

So, the atoms present in 3.00mm^2 will be:

In 3.00mm^3 of gold, there are 1.77x10^20 atoms

Answer: 1.77x10^20 atoms

Answer:

Hi there!

Your answer is:

In a solar eclipse, we see two types of shadows. One is the "umbra" or the darkest shadow caused by the sun. It's located in the center.

The "penumbra" in a solar eclipse is the shadow that's lighter and located on the sides of the earth. Think about it like this:

The sun and earth are in line. The darkest shadow will continue in that line. That is the umbra. The penumbra continues directly on the outside of the umbra. It's lighter that the other shadow!

A penumbra solar eclipse is when the sun, moon, and earth DONT align properly. This causes a partial eclipse, not a full eclipse. A penumbra solar eclipse is a Partial solar eclipse.

Hope this helps! To be clear, none of this is copied. This is based off of my previous knowledge on the subject and interest in phenomena such as these!

if the grass will be replanted and transported pet store mice to dwell on the hill.No, their solution does not meet all of their needs.

One reason is that, even if the grass is replanted, it may still wash away in future heavy rains if the underlying soil erosion problem is not addressed. The students should consider ways to stabilize the soil and prevent erosion, such as building terraces or planting vegetation that can hold the soil in place. Additionally, bringing pet store mice may not be a good solution since mice are not native to that area and could cause problems for the local ecosystem.

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Approximately 3.04 grams of magnesium would be required to react with 0.25 moles of hydrochloric acid.

To determine the mass of Mg required, we need to use the balanced chemical equation for the reaction between hydrochloric acid (HCl) and magnesium (Mg):

2HCl + Mg → MgCl2 + H2

From the balanced equation, we can see that 2 moles of HCl react with 1 mole of Mg. Therefore, if 0.25 mol of HCl reacts, we would need half of that amount, which is 0.125 mol of Mg.

To calculate the mass of Mg required, we need to multiply the number of moles of Mg by its molar mass. The molar mass of Mg is given as 24.31 g/mol. Therefore, the mass of Mg required can be calculated as follows:

Mass of Mg = Number of moles of Mg × Molar mass of Mg

Mass of Mg = 0.125 mol × 24.31 g/mol

Mass of Mg = 3.04 g

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The treatment requirement (% removal) in the agricultural waste discharge to achieve 50mg/L concentration in the withdrawal location 80 km downstream is 99.57%

a. Control Volume

The schematic diagram of the control volume is given below.

b. Steady-state Phosphate concentration in water withdrawn 90 km downstream

The steady-state phosphate concentration in the water withdrawn 90 km downstream is given by:

C2 = (Q1C1 + Q2C2)/(Q1 + Q2)

Where,

C2 = Concentration of phosphate in the water withdrawn 90 km downstream

C1 = Concentration of phosphate in the upstream water (25 ppm)Q1 = Upstream flow (40 m 3/s)Q2 = Agricultural discharge (2.5 m^3/s)C2 = ((40 x 25) + (2.5 x 1000)) / (40 + 2.5)C2 = 59.3 ppm

Therefore, the steady-state phosphate concentration in the water withdrawn 90 km downstream is 59.3 ppm.c. Treatment requirement (% removal) in the agricultural waste discharge to achieve 50mg/L concentration in the withdrawal location 80 km downstream

The concentration of the waste-stream that will produce 50mg/L downstream concentration is given by:

50 = (Q1C1 + Q2C2)/(Q1 + Q2)C2 = ((40 x 25) + (2.5 x C2))/(40 + 2.5)50 = (1000 x 2.5) / (40 + 2.5) + (40 x 25) / (40 + 2.5)C2 = 4.3 ppm

The % removal from the difference of the influent wastewater concentration with respect to the initial waste-stream concentration is given by:

% removal = (C in - C out) / C in x 100Where,Cin = Influent wastewater concentration (1000 ppm)

C out = Concentration of waste-stream required to produce 50 ppm downstream concentration (4.3 ppm)\% removal = (1000 - 4.3) / 1000 x 100\% removal = 99.57%

Therefore, the treatment requirement ( % removal) in the agricultural waste discharge to achieve 50mg/L concentration in the withdrawal location 80 km downstream is 99.57%.

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Answer:

A. the average kinetic energy increases

Explanation:

temperature is a measure of the average kinetic energy of the particles in a sample of matter

Answer:Ocean currents act much like a conveyor belt, transporting warm water and precipitation from the equator toward the poles and cold water from the poles back to the tropics.

Explanation:

Answer:

Explanation:

Ocean currents act much like a conveyor belt, transporting warm water and precipitation from the equator toward the poles and cold water from the poles back to the tropics. 

hope it helps!

Answer:

not sure

Explanation:

Glycinate donates an electron pair so it is a bidentate ligand.

The molecular formula is C₂H₄NO₂⁻. The octahedral complex is formed between glycinate molecules and cobalt(III) and the stoichiometry of the complex is [Co(gly)₃]. The reaction is as follows;

Co₃⁺(aq) + 3C₂H₄NO₂⁻ ⇒ [Co(C₂H₄NO₂⁻](aq)

A cobalt complex is formed when 3 glycinate ions equivalents react with one Co₃⁺ ion equivalent so, it is necessary to keep the glycinate ions concentration greater than the cobalt(III) ions at least three times more.

So, taking the concentration 4 times greater can facilitate the reaction.

For a complex whose concentration is 0.015M, 0.06M glycinate ions are required to obtain the desired cobalt(III) glycinate complex.

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The percent yield for the production of nitrogen dioxide can be calculated using the formula: Percent yield = (actual yield / theoretical yield) x 100. In this case, the actual yield is given as 1,500 kg of nitrogen dioxide per day, and the theoretical yield can be determined based on the stoichiometry of the reaction.

From the balanced equation, we can see that the stoichiometric ratio between nitrogen oxide (NO) and nitrogen dioxide (NO2) is 2:2. Therefore, for every 2 moles of nitrogen oxide consumed, 2 moles of nitrogen dioxide are produced.

To calculate the theoretical yield, we need to convert the given mass of nitrogen oxide to moles. The molar mass of nitrogen oxide (NO) is 30 g/mol, so 1,500 kg is equal to 50,000 moles. Since the stoichiometric ratio is 2:2, the theoretical yield of nitrogen dioxide is also 50,000 moles.

Now we can calculate the percent yield:

Percent yield = (1,500 kg / 50,000 moles) x 100 = 3%

Therefore, the percent yield for the production of nitrogen dioxide is 3%. None of the given answer options match this result, so it seems there might be an error in the provided choices.

The given chemical equation represents the combustion of nitrogen oxide to produce nitrogen dioxide. According to the stoichiometry of the reaction, 2 moles of nitrogen oxide react with 1 mole of oxygen gas (O2) to produce 2 moles of nitrogen dioxide (NO2).

In the plant, it is stated that 1,500 kg of nitrogen oxide is consumed per day to produce an equal amount (1,500 kg) of nitrogen dioxide per day. To determine the percent yield, we need to compare the actual yield (1,500 kg) to the theoretical yield.

To calculate the theoretical yield, we need to convert the given mass of nitrogen oxide to moles. The molar mass of nitrogen oxide is calculated to be 30 g/mol. By dividing the mass of nitrogen oxide (1,500 kg) by its molar mass (30 g/mol), we find that there are 50,000 moles of nitrogen oxide consumed.

Since the stoichiometry of the reaction tells us that the ratio between nitrogen oxide and nitrogen dioxide is 2:2, the theoretical yield of nitrogen dioxide is also 50,000 moles.

Finally, we can calculate the percent yield using the formula: Percent yield = (actual yield / theoretical yield) x 100. Substituting the values, we get (1,500 kg / 50,000 moles) x 100 = 3%.

Therefore, the percent yield for the production of nitrogen dioxide in the given plant is 3%, which does not match any of the provided answer options.

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Answer:

Graphing data can help you to recognize changes in what your doing.

Explanation:

Answer:

Explanation:

To identify trends, make predictions, and recognize anomalous data. Helps you understand what your data means or a picture of your graph. A graph wich the points form a straight line.

Answer:

Explanation:

Decomposition reaction, also known as analysis or dissociation, is a type of chemical reaction in which a compound breaks down into simpler substances or elements. In this reaction, a single reactant undergoes a chemical change and produces two or more products.

The decomposition reaction can be represented by the general equation:

AB → A + B

Where AB is the reactant, and A and B are the products. The reactant AB is usually a compound, and it breaks down into its constituent elements or simpler compounds.

There are different types of decomposition reactions, including:

Thermal decomposition: It occurs when a compound is heated, resulting in its decomposition into simpler substances. For example, the thermal decomposition of calcium carbonate (CaCO3) produces calcium oxide (CaO) and carbon dioxide (CO2):

CaCO3 → CaO + CO2

Electrolytic decomposition: It takes place when an electric current is passed through an electrolyte, causing it to break down into its component ions. For instance, the electrolysis of water (H2O) leads to the decomposition into hydrogen gas (H2) and oxygen gas (O2):

2H2O → 2H2 + O2

Photochemical decomposition: It occurs when a compound undergoes decomposition due to exposure to light energy. Chlorine gas (Cl2) can decompose into chlorine atoms (Cl) under the influence of light:

Cl2 → 2Cl

These are just a few examples of decomposition reactions. They are important in various chemical processes and are used in industries, laboratory experiments, and natural phenomena. By understanding and controlling decomposition reactions, scientists can gain insights into the behavior of different compounds and develop practical applications in fields such as chemistry, materials science, and environmental science.

Answer:

Explanation:

reaction in which a compound breaks down into simpler substances or elements

Answer:

Map scale refers to the relationship (or ratio) between distance on a map and the corresponding distance on the ground.

Explanation:

For example, on a 1:100000 scale map, 1cm on the map equals 1km on the ground.

Answer:

5 grams < 9.4 grams < 0.35 kilograms

Explanation:

Kilograms (Kg) and grams (g) are both units of measurement for MASS quantity. However, these units are not the same as they vary in magnitude. The kilograms is bigger unit of measurement than the grams. 1000grams makes 1kilograms.

According to this question, 0.35 kilograms 9.4 grams and 5 grams are to be arranged in ascending order i.e. from smallest to largest. First, we need to change all the units to the same.

We change 0.35kg to g

Since 1000g = 1kg

Then, 0.35kg = 0.35 × 1000

= 350g.

Rearranging the values, we have:

5 grams < 9.4 grams < 0.35 kilograms

Answer:

Test for carbon dioxide gas.

Explanation:

The reaction between baking soda and citric acid will form sodium ions, citric acid ions, carbon dioxide gas, and water. So all you have to do is add the gas produced (by gas displacement method or something) and test whether the gas is carbon dioxide, with lime water or other methods like hydrogencarbonate indicator. Hope this helped!

PLEASE GIVE BRAINLIEST

On mixing citric acid and baking soda a chemical reaction takes place which is indicated by the evolution of carbon dioxide gas .

Chemical reactions are defined as reactions  which occur when a substance combines with another substance to form a new substance.Alternatively, when a substance breaks down or decomposes to give new substances it is also considered to be a chemical reaction.

There are several characteristics of chemical reactions  like change in color, change in state , change in odor and change in composition . During chemical reaction, there is also formation of precipitate an insoluble mass of substance or even evolution of gases.

There are three types of chemical reactions:

1) inorganic reactions

2)organic reactions

3) biochemical reactions

During chemical reactions atoms are rearranged and changes are accompanied by an energy change as new substances are formed.

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Answer:

I have a picture from my excerpt that basically answers all of that!

Hope it helps!

Explanation:

The attachment

The alkali metals and alkaline earth metals has different physical and chemical properties due to difference in their valence electrons.

·Electronic      [Noble gas]ns1                                  [Noble gas]ns2

configuration

·Reactivity      Comparatively more reactive     Comparatively less

                                                                         reactive                        

·Hardness       Soft and can be cut by sharp     Comparatively harder

                      knife

·Valency         One valence electron               Two valence electron

·Ionic charge   +1                                              +2

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Answer:

2

Explanation:

The 1 & 2 are both signifigant becuase they are presented in scientific notation.

Answer:

About 203.381 grams

Explanation:

We need to first determine the molar mass of Ba3(PO4)2.

We have:

3 Bariums - 137.327*3 = 411.981

2 Potassiums - 39.098*2 = 78.198

8 Oxygens - 16*8 = 128

Add these together and we get 618.179 g/mol

If we only want 0.329 moles, then we multiply those two numbers together to get about 203.381 grams.

Answer:

A co-transported molecule travels down an electrochemical gradient in either direction.

The coupled transport allows a molecule to be transported against the electrochemical gradient as Co-transported molecules can move in either direction along an electrochemical gradient. This is further explained below.

Generally, coupled transport is simply defined as the simultaneous passage of two substances over a biological membrane.

In conclusion, Because molecules that are co-carried can travel in either way along an electrochemical gradient, linked transport enables molecules to be transported in the opposite direction of the electrochemical gradient.

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Answer:

Too much iodine can be harmful if you don't need it. You don't need to take iodine (supplements) if you already have a varied and balanced diet.

Explanation:

Iodine is already contained in table salt so you don't need to add any more.

Because the molecules are more closely spaced, the solid occupies less space than the same substance when it is in a gaseous state.

In the electron transport chain, electrons are passed from redox center to redox center (a) with the assistance of a carrier protein. The electron transport chain is a series of protein complexes embedded in the inner mitochondrial membrane (in eukaryotes) or the plasma membrane (in prokaryotes).

These protein complexes contain redox centers, such as iron-sulfur clusters or heme groups, which can accept and donate electrons. The electrons are transferred from one redox center to another through a series of oxidation-reduction reactions. Carrier proteins, such as cytochromes or flavoproteins, facilitate the movement of electrons between the redox centers.

As the electrons are passed along the chain, they move from lower to higher energy states, releasing energy in the process. The movement of electrons is not spontaneous but rather driven by the redox potential gradient created by the transfer of electrons.

This redox potential gradient is established by the movement of protons (H+) across the membrane, which is coupled to electron transport and creates a proton gradient used for ATP synthesis. So, option (a) with the assistance of a carrier protein is the correct answer.

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Carbon dioxide cannot be liquefied above the critical temperature, even when high pressure is applied. The critical temperature is the highest temperature at which a substance can be liquefied by increasing the pressure. For carbon dioxide, the critical temperature is approximately 31.1°C (87.98°F). Above this temperature, carbon dioxide remains in the gaseous state regardless of the pressure applied.

Carbon dioxide or carbonic acid is a chemical compound consisting of two oxygen atoms covalently bonded to a carbon atom. It is a gas at standard temperature and pressure conditions and is present in the Earth's atmosphere.

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Answer:

Explanation:

Because they have electrical cords  :P    But really,  b/c electron movement is a convenient attribute of many elements.   The electrons are "loose"  on most metals, so they can conduct electricity.  

Answer:

The benefits of power electronics are: High power density power supplies. Improved efficiency of up to 99% in power conversion. Noise-sensitive applications such as in medical devices are also transitioning to switching power supplies because of the efficiency and reliability.