Which observation most likely indicates that only a chemical change has taken place?.

Answer:

Explanation:

Mide 2mL de etanol, añadelo a un matraz aforado, pon agua hasta llegar a 100mL

Answer:

108 inches

Had the same question.

Answer:

Cellulose stimulates the work of intestines and increases their discharge.

Explanation:

Cellulose is a polysaccharide made of glucose polymers, which build plant fibers. Because of this, the plants possess their firmness.

Humans do not digest cellulose because they do not possess certain enzymes, but it is useful for their digestion because it stimulates the work of the intestines.

Cellulose enhances intestinal peristalsis. Peristalsis is series of contractions that allow the progressive movement of food through the digestive tract.

The concentration of \(OH^-\) in a solution with an \(H^+\) concentration of \(7.9*10^{-5\) M is 1.26 * \(10^{-10}\)

\(K_w\) is the ionization constant of water. It is constant for a temperature and can be expressed as the product of the concentration of H+ and OH- ion in the solution. It only changes with a change in temperature.

At 25°C, \(K_w\) = \(10^{-14\)

\(K_w\) = [H+][OH-]

taking negative logs on both sides

p\(K_w\) = pH + pOH

14 = pH + pOH

In the question,

[H+] = \(7.9*10^{-5\) M

pH = 4.1

14 = 4.1 + pOH

pOH = 9.9

Taking the negative anti-log of the above

[OH-] = 1.26 * \(10^{-10}\)

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Answer:

The thermal decomposition of ammonium nitrate to produce dinitrogen monoxide and water. This reaction takes place at a temperature of 200-260°C.

Answer:

cyclohexene I think that's the answer

This exercise is from Barbershop can keep men healthy by Joseph Ravenell, and is related to High Blood Pressure.

Mr. Ravenell describes the essence of the black barbershop as a place where there is friendship, trust and cooperation, and peace. (1a)

He considers it a safe haven because is void of stress and societal threats. (1b)

Some of the health-related topics that were discussed in the barbershop include but are not limited to:

Denny states that black men trust their barbers more than their doctors because most of them relate more with their barbers than with their doctors.

Mr. Ravenell taught barbers how to measure blood pressure, and how to counsel their customers to go see a doctor if their blood pressure was too high.

It was discovered that the number of those whose blood pressure were controlled in the 18 shops that were studied for one year were higher in the shops where the barbers had been trained.

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Answer:

it's a chemical Element

Explanation:

symbol He

atomic number 2.

Answer:

Choux pastry

Explanation:

Eclairs are a long, thin pastry made from choux pastry and is filled with cream and topped with icing (usually chocolate).

I hope this helps!!

- Kay :)

Long French pastries composed of choux pastry, filled with custard or pastry cream, and covered with fondant icing are known as éclairs.

The fundamental components for choux dough, including as sugar, butter, flour, milk, and egg, are used to make eclairs, cream puffs, and profiteroles. However, it is crucial to read and follow the directions carefully to prevent common eclair blunders such . Eclair shells with broken surfaces.

A choux pastry-based éclair is a long, thin individual cake. This delicious treat is loaded with cream and covered with milk chocolate. A donut is a fried sweet treat made of sweet dough that is often shaped like a ring or ball.

The chocolate éclair, which is covered with chocolate fondant and filled with chocolate custard or pastry cream, is possibly the most well-known type of éclair.

Thus, éclair is made up of choux pastry.

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In order to generate X-rays, it is necessary to use the kα transition (2p→1s) in copper.

This is because this transition has a lower energy level than the 4s→3p transition, which means that it is easier to achieve the necessary energy levels to generate X-rays.

Additionally, the kα transition is a more efficient means of generating X-rays because it involves the emission of a photon with a higher energy level than the 4s→3p transition.

Therefore, using the kα transition in copper is the most practical and efficient way to generate X-rays.

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We have to calculate the number of moles in 28g of nitrogen. Here the number of moles will be 1 and there will be 6.022×10²³ molecules.

Number of moles can be defined as the ratio between the amount of substance to the molar mass. Nitrogen  molecule is a diatomic molecule. It means there are two nitrogen atoms in the molecule.

So molar mass of nitrogen = 2× 14 = 28g

That means a mole of nitrogen will weigh 28 g.

So we can say that the number of moles in 28g of nitrogen is 1.

Or else we can use the equation

Number of moles = Amount of substance/ molar mass

                                     = 28/28 = 1

So, 28 g of nitrogen means 1 mole of nitrogen,

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In order to calculate the number of moles of HI (hydrogen iodide) at equilibrium, we need to use the given values and the equilibrium constant (Kc) of the reaction. From the balanced equation H₂(g) + I₂(g) ⇌ 2HI(g).

We can see that the stoichiometry of the reaction is 1:1:2 (H₂:I₂:HI).

Moles of H₂ (nH₂) = 1.33 mol.

Moles of I₂ (nI₂) = 1.33 mol.

The volume of the flask (V) = 4.00 L.

Temperature (T) = 449°C = 449 + 273 = 722 K.

To calculate the number of moles of HI at equilibrium, we need to use the equation: Kc = ([HI]^2) / ([H₂] × [I₂]).

[HI]^2 = Kc × [H₂] × [I₂].

Now we can substitute the given values and calculate the number of moles of HI:

[HI]^2 = Kc × (nH₂) × (nI₂) = Kc × (1.33 mol) × (1.33 mol).

Taking the square root of both sides: [HI] = √(Kc × (1.33 mol) × (1.33 mol)).

It is noted that the value of the equilibrium constant Kc is needed to perform the final calculation.

If you have the specific value of Kc, you can substitute it into the equation to find the number of moles of HI at equilibrium.

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Water boiling is not a chemical reaction because it does not involve a chemical bond being broken or formed. During boiling, the water molecules absorb heat energy and gain enough kinetic energy to escape into the air as a gas, in the form of water vapor. This process is known as a physical change because it does not alter the chemical makeup of the water molecules, it only changes their physical state from liquid to gas.

Answer:

80.5 atm

Explanation:

First of all, we convert 28.0 °C and 50.0 °C into K:

To answer this problem we'll use Gay-Lussac's Law, which states that:

In this case:

We put the data:

And solve for P₂:

Thus, the correct answer is 80.5 atm.

The Nernst equation relates the standard emf of a cell reaction to the equilibrium constant and the reaction quotient Q:

E = E° - (RT/nF) * ln(Q)

At equilibrium, the reaction quotient Q is equal to the equilibrium constant K:

E = E° - (RT/nF) * ln(K)

We can rearrange this equation to solve for n:

n = (RT / F) * ln(K) / (E° - E)

Plugging in the given values:

E° = +0.17 V

K = 5.5 * 10^5

T = 298 K

R = 8.314 J/(mol*K)

F = 96485 C/mol

n = (8.314 J/(mol*K) * 298 K / 96485 C/mol) * ln(5.5 * 10^5) / (0.17 V - 0 V)

n ≈ 4.

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Answer:

Explanation:

Sadly there is no combination of elements to spell this. You could start with Aluminium which is AL but there A or N on the table.

Organic chemistry have a wide variety from compounds of the presence of two elements namely

The main variety of compounds exists in the combination of carbon and hydrogen forming hydrocarbons which are the basis of life and present in cells  making them virtually everywhere around us.

 Organic molecules in itself comprises of multiple chains of carbon atoms with different  lengths and because of the ability of carbon to bond with many elements, This produces  a variety of compounds which no other atom or element can.

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The pressure exerted by the neon gas, when the volume is increased from 7.2 mL to 28.8 mL at constant temperature, can be calculated using Boyle's Law. The pressure exerted by the neon gas, when the volume is increased to 28.8 mL at constant temperature, is 0.375 atm.

Boyle's Law states that at constant temperature, the product of the pressure and volume of a gas remains constant. Mathematically, it can be expressed as P₁V₁ = P₂V₂. This law allows us to calculate the change in pressure when the volume changes.

In this case, the initial volume (V₁) is given as 7.2 mL, and the initial pressure (P₁) is 1.5 atm. The final volume (V₂) is 28.8 mL. By substituting these values into Boyle's Law equation, we can solve for the final pressure (P₂).

When we perform the calculations, we find that the pressure exerted by the neon gas, when the volume is increased to 28.8 mL, is 0.375 atm. As the volume increases, the pressure decreases due to the inverse relationship between pressure and volume.

Using Boyle's Law: P₁V₁ = P₂V₂

Given:

Initial volume (V₁) = 7.2 mL

Initial pressure (P₁) = 1.5 atm

Final volume (V₂) = 28.8 mL

To find the final pressure (P₂):

P₂ = (P₁ * V₁) / V₂

  = (1.5 atm * 7.2 mL) / 28.8 mL

  = 0.375 atm

Therefore, the pressure exerted by the neon gas, when the volume is increased to 28.8 mL at constant temperature, is 0.375 atm.

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1.  the final concentration of NaOH after adding 125 mL of water to 45.3 mL of 0.71 M NaOH solution is approximately 0.189 M.

2.  the final concentration of KOH after adding 550 mL of water to 125 mL of 3.01 M KOH solution is approximately 0.557 M.

1.) If 125 mL of water is added to 45.3 mL of a 0.71 M NaOH solution, the resulting solution will be a diluted NaOH solution. The addition of water will increase the total volume while reducing the concentration of NaOH. To determine the final concentration of NaOH, we need to consider the conservation of moles.

First, let's calculate the moles of NaOH in the initial solution:

moles of NaOH = volume (in L) × concentration (in M)

moles of NaOH = 0.0453 L × 0.71 M = 0.0321433 moles

After adding 125 mL (0.125 L) of water, the total volume of the solution becomes 0.0453 L + 0.125 L = 0.1703 L.

To find the final concentration, we divide the moles of NaOH by the total volume:

final concentration of NaOH = moles of NaOH / total volume

final concentration of NaOH = 0.0321433 moles / 0.1703 L ≈ 0.189 M

Therefore, the final concentration of NaOH after adding 125 mL of water to 45.3 mL of 0.71 M NaOH solution is approximately 0.189 M.

2.) If 550 mL of water is added to 125 mL of a 3.01 M KOH solution, the resulting solution will also be a diluted solution. Again, we will apply the conservation of moles to determine the final concentration of KOH.

First, calculate the moles of KOH in the initial solution:

moles of KOH = volume (in L) × concentration (in M)

moles of KOH = 0.125 L × 3.01 M = 0.37625 moles

After adding 550 mL (0.55 L) of water, the total volume of the solution becomes 0.125 L + 0.55 L = 0.675 L.

To find the final concentration, divide the moles of KOH by the total volume:

final concentration of KOH = moles of KOH / total volume

final concentration of KOH = 0.37625 moles / 0.675 L ≈ 0.557 M

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Answer: Because it is cold.

Explanation: Brainliest?? LOL

Answer:

R = 8.314 pKa*L/mol*K

The value for the ideal gas constant (R) is approximately 8.314 kPa·L/(mol·K).

To determine the value for the ideal gas constant (R) when pressure (P) is in kilopascals (kPa), temperature (T) is in kelvins (K), volume (V) is in liters (L), and amount of gas (n) is in moles, we need to use the appropriate units for R based on these measurements.

The ideal gas constant, R, can be expressed in various units. The most common units for R are:

R = 0.0821 L·atm/(mol·K) (atmospheres, liters, moles, and kelvins)

However, since you provided the measurements in kilopascals, liters, moles, and kelvins, we need to use a different value for R that is consistent with these units:

R = 8.314 kPa·L/(mol·K)

Therefore, when pressure is in kilopascals, volume is in liters, amount of gas is in moles, and temperature is in kelvins, the value for the ideal gas constant (R) is approximately 8.314 kPa·L/(mol·K).

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Answer:

1.) Elements: building blocks of the universe

2.) Atoms: basic blocks of all matter

3.) Molecules: is matter. Made of atoms

Answer:

Explanation:

1.) Elements: building blocks of the universe

2.) Atoms: basic blocks of all matter

3.) Molecules: is matter. Made of atoms

After, after 12 hours, we would anticipate roughly 27 mutations to be present in the S. aureus population in your foot wound.

Part 1-

First, the size of the S. aureus population in the wound in your foot should be found. Let's assume that the population size is 1 million (1 x 10^6) cells.

The  mutations estimated in one generation per cell are:

1 mutation per 10¹⁰base pairs

The base pairs in the genome of S. aureus are 2.8 x 10⁶

Therefore, the expected number of mutations per generation per cell is:

(2.8 x \(10^{6}\)) / (\(10^{10}\)) = 2.8 x \(10^{-4}\) mutations per cell per generation

To estimate the number of mutations in the population which occur after 12 hours the number of generations that have passed needs to be known. The generation time of  S. aureus is approximately 30 minutes, so the number of generations in 12 hrs (hours) will be:

12 hrs x (60 minutes/hr) / (30 minutes/generation)

= 24x4 equals 96 generations

In 96 generations the approximate number of mutations per cell is:

96 generations x 2.8 x \(10^{-4}\) mutations per cell per generation

= 0.027 mutations per cell

If we multiply mutations per cell by the number of cells in the population, to know the total number of mutations in the population:

i.e.,0.027 mutations taking place per cell x 1 x 10⁶ cells gives 27 mutations

Therefore, after 12 hours, we can expect approximately 27 mutations to be present in the population of S. aureus inside the wound in your foot.

Estimatedly, 0.0028 mutations will take place per cell in the population. After the end of 12 hours, 0.0028 * 16,777,216 = 46,976 new mutations will exist.

Part 2-

The implications of this genetic diversity in the context of treating possible infections is that host genetic diversity is thought to reduce the possibility that the disease will widen in natural populations.

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Answer:

29 grams

Explanation:

At 20°C, a saturated solution of sodium nitrate (NaNO3) contains 86 grams of solute in 100 m of water.

This means the solubility of NaNO3 at  20°C is 86 g/100 ml of water

The solubility of NaNO3 at 50 °C is 115 grams of NaNO3/100 ml of water.

Therefore; to get the amount of sodium nitrate must be added to saturate the solution at 50°C;

We subtract the solubility at 20°C  from the solubility at 50 °C

That is; 115 g/100 ml of water - 86 g/100 ml of water

         = 29 grams of NaNO3

Lisa observed individual differences in the rate of hair growth and aims to investigate whether Rogooti affects the speed of hair growth.

What is Lisa's observation about hair growth?

Lisa's observation that some hair grows faster than others is not unusual since hair growth rates can vary depending on several factors, such as genetics, age, and overall health.

However, her interest in investigating the effects of Rogooti on hair growth is an attempt to determine if the commercial hair product can influence hair growth rates. This research question is relevant to individuals who are seeking ways to improve their hair growth and may consider using commercial hair products as a possible solution.

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Because NaCl takes more energy to break it's bigger.

For NaCl, the structure or lattice formation enthalpy is -787 kJ mol-1. Therefore, the lattice dissolution enthalpy is always positive and the lattice formation enthalpy is always negative. The reason that NaCl has the highest lattice enthalpy is that for similar anions, cations with smaller radii have higher lattice enthalpies.

If we want to talk about the amount of energy released when a lattice forms from scattered gas ions we should use the lattice formation enthalpy. MgO has a higher lattice energy because each ion carries two unit charges compared to one in NaCl. NaCl is a compound with higher lattice energy. Description Lattice energy is defined as the energy released when the combination of its constituent ions forms one mole of an ionic compound.

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At 35 K temperature would atoms of aHe(g) sample have the greatest average kinetic energy

The relationship between the average kinetic energy of gas particles and temperature is direct.

In comparison to other fundamental states of matter, plasma has the highest kinetic energy. This is due to the fact that particles in a plasma travel more quickly than those in a corresponding solid, liquid, or gas.

The relationship between the molecules' average kinetic energy and Kelvin temperature is direct. 12mv2=kT, where k is a constant of proportionality. The velocity v is constant if the temperature T and the molecular mass m are both constant.

The gas molecules travel more quickly as the temperature rises, which increases their kinetic energy. Gases have the same kinetic energy at any temperature.

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