Which pair is classified as pure substances? a. compounds and solutionsc. elements and mixtures b. mixtures and solutionsd. compounds and elements

Answer:

electrical and heat energy

Explanation:

Answer:

Heat and Light

Explanation:

C on usatp

Answer:

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

\(n = \frac{N}{L} \\ \)

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

\(n = \frac{4.23 \times {10}^{25} }{6.02 \times {10}^{23} } \\ = 70.265780...\)

We have the final answer as

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Answer:

The first law of thermodynamics doesn't actually specify that matter can neither be created nor destroyed So yes we can create matter because matter is every where buildings ,structures etc. So the answer is yes!

Explanation:

                         Hope this helped!ヾ(•ω•`)o❤

Answer:

D. A federal government agency publishes an article in a professional scientific journal detailing technical details of a  new virus.

Explanation:

Public scientific communication is a way used by scientists to make the audience able to understand the basics of science to communicate an informed decision. There are several skills under public scientific communication that include connect with the public, talk to journalists, make science understandable, and understand the audience.

The best way to connect with the audience is to publish an article in a professional scientific journal because mostly journals are peer-reviewed having standard of quality.

A federal government agency informing about a  new virus through an article in a professional scientific journal is the best way of public scientific communication as it will be for a specific audience along with a standard of quality.

Hence, the correct answer is "D".

If we have 5 grams of salicylic acid and the filter paper weighs 0.354 g and the dry filter paper with the aspirin is 2.711 g, then the aspirin yield is 47.14%.

To determine the aspirin yield, we need to calculate the mass of the aspirin formed. The yield can be calculated using the formula:

Yield = (Mass of aspirin obtained / Initial mass of salicylic acid) × 100

Mass of salicylic acid = 5 grams

Mass of filter paper = 0.354 grams

Mass of filter paper with aspirin = 2.711 grams

To find the mass of the aspirin, we need to subtract the mass of the filter paper from the total mass:

Mass of aspirin = Mass of filter paper with aspirin - Mass of filter paper

Mass of aspirin = 2.711 g - 0.354 g = 2.357 g

Now we can calculate the yield:

Yield = (2.357 g / 5 g) × 100

Yield = 47.14%

Therefore, the aspirin yield is 47.14%.

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n=3 is the energy level to have a d sublevel because There is a s orbital for each primary energy level. There is a p sublevel in the second major energy and all higher energy levels.

Simple Units. Joule (Q) (J). This is the fundamental energy element of the measurement measurements, or the Worldwide System of Units in a later, more thorough version (SI). In the end, the meter, kilograms, and second are used to characterize it.

The wave nature of particles leads to quantized energy levels, which establish a correlation between a molecule's energy and wavelength. The resonant frequencies that have accurately characterized energies for a confined particle, such an atom in an atom, have the shape of a standing wave.

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Answer:

Atom

Explanation:

An atom is the smallest unit which represents the an element.

It retains the chemical properties of an element.

Explanation:    The relocation of organisms across geographical boundaries occurs naturally by various means. Since humans began exploring the globe, however, the rate of new species being introduced into regions has greatly increased. In some cases, humans have dispersed species on purpose; for instance, many plants were transported from Europe to North America for agricultural and ornamental purposes. Others were transported accidentally by ship, train, airplane - even on the shoes of hikers.

     Some species may be introduced and not be able to survive in their new habitat. Others may find optimal conditions for growing, reproducing, and adapting to the new environment, and their populations soar. For instance, lack of predators may contribute to their rapid population increases.

The correct answer is option C. These interactions only occur if hydrogen is bonded to nitrogen, oxygen, and fluorine.

Hydrogen bonds are a special type of dipole-dipole interaction that occurs between a hydrogen atom covalently bonded to an electronegative atom (such as nitrogen, oxygen, or fluorine) and a lone pair of electrons on another electronegative atom. This results in a particularly strong dipole-dipole interaction, which is why hydrogen bonds are considered a special class of these interactions.

While hydrogen bonds are observed with many molecules that contain hydrogen, they are not observed with all molecules that contain hydrogen. Additionally, they are not necessarily stronger or weaker than other types of dipole-dipole interactions, but they do account for the higher melting and boiling points observed for certain molecules, such as water.

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Answer:

About 500

Explanation:

Bc i used my calc

The neutral organic product obtained from the reaction is propene (CH3CH=CH2)

The given reaction involves the dehydration of 1-propanol (CH3CH2CH2OH) in the presence of concentrated sulfuric acid (H2SO4) at 200°C. Dehydration is the removal of a water molecule from the alcohol compound. In this case, 1-propanol loses a water molecule to form propene (CH3CH=CH2), which is an alkene.

The neutral organic product resulting from this reaction is propene (CH3CH=CH2). The reaction occurs as the hydroxyl group (-OH) of 1-propanol is protonated by the acidic H2SO4, leading to the loss of a water molecule. This creates a double bond (C=C) between the second and third carbon atoms, resulting in the formation of propene.

Thus, the neutral organic product obtained from the reaction is propene (CH3CH=CH2).

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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

Phospholipase-C is activated, which cleaves PI(4,5)P2 to release IP3. IP3 binds to a specific receptor on the endoplasmic reticulum, which triggers the release of Ca2+ into the cytoplasm.

What is cytosolic ca2+ ?

Endothelial cells use the intracellular calcium ion, or [Ca2 I as a crucial second messenger to control migration, proliferation, inflammation, vasodilation, and cell survival.

[Ca2+]i is returned to resting levels in smooth muscle cells via ATP-dependent Ca2+ pumps in the SR and plasma membrane, as well as by the plasma membrane Na+-Ca2+ exchanger, after the removal of a contractile stimulus.

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Answer:

1 mole = 6.02 x 1023 atoms = 6,158.46 atoms

1 mole = 12 g

1Oz = 28.3495 g

1.25 moles = 1.25*12 = 15g

15g = 15*6,158.46 = 92,376.9 atoms

92,376.9 atoms (in g) = around 3258.49 atoms (in OZ)

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The amount of titanium-44 remaining will be 1/4 of the original amount, or 0.150 g.

Amount is a quantity or magnitude of something, typically money. For example, a person may refer to the "amount of money" they have saved, the "amount of time" it takes to do something, or the "amount of food" they have purchased. Amount can also refer to the total number of something, such as the "amount of people" who have attended an event or the "amount of work" that needs to be done.

The half-life of titanium-44 is 60.0 y, meaning that after every 60.0 y, the amount of titanium-44 will be halved.
0.600 g - 0.150 g = 0.450 g

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Answer:

C) 0.121 M

Explanation:

HCl + H₂O = H₃O⁺ + OH⁻

.121M              .121M

HCl is a strong acid . It will dissociate almost 100 % so the concentration of acid and hydronium ion formed will be equal . It is to be noted that hydronium ion is formed due to association of H⁺ and H₂O . H⁺ is formed due to ionisation of HCl .

So concentrtion of hydronium ion ( H₃O⁺ ) will be .121 M.

1. The complete electron configuration for the chromium atom (Cr, atomic number 24) is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d⁵

2. Using NOBLE GAS notation, the electron configuration for the zinc atom (Zn, atomic number 30) is: [Ar] 4s² 3d¹⁰

3. The complete electron configuration for the potassium atom (K, atomic number 19) is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹

4. Using NOBLE GAS notation, the electron configuration for the nitrogen atom (N, atomic number 7) is: [He] 2s² 2p³

5. The complete electron configuration for the vanadium atom (V, atomic number 23) is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d³

6. Using NOBLE GAS notation, the electron configuration for the scandium atom (Sc, atomic number 21) is: [Ar] 4s² 3d¹

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Iron III oxide and lead II oxide

They are both ionic

Oxides are a class of chemical compounds that contain one or more oxygen atoms combined with other elements. They can be formed by the combination of oxygen with most elements in the periodic table, including metals, nonmetals, and metalloids.

Oxides are important in many industrial and technological applications. For example, metal oxides are commonly used as catalysts, pigments, and in the production of ceramics, while nonmetal oxides are used in the production of acids and inorganic salts.

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How many oxidising reactions take place during glycolysis, assuming that each happens just once following the aldolase-catalyzed public response? Glyceraldehyde 3-phosphate dehydrogenase is the enzyme that catalyses the reaction that converts glyceraldehyde into 1,3-bisphosphate.

a chemical process that occurs when an object comes into touch with air or another oxidizer. Rust and an apple's brown colour were examples of oxidation. There is an oxidation process when oxygen interacts with a material or an element. The process of removing oxygen from the gaseous reactants is another definition of oxidation. A molecule, molecule, or ions undergoes oxidation when it releases electrons.

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The defining characteristic of a condensation reaction is that two monomers are covalently bonded together and a water molecule is produced (Option A).

A condensation reaction occurs when two small molecules, known as monomers, react with one another to form a larger molecule, known as a polymer, by releasing a water molecule. Because water is removed, the reaction is also known as a dehydration reaction. The process, which can be repeated many times to form long chains of polymers, is the mechanism by which biopolymers such as proteins, carbohydrates, and nucleic acids are formed.

Option B, two monomers are covalently bonded together and a water molecule is used up, is incorrect.

Option C, a polymer is broken down into monomers and a water molecule is produced, which is a hydrolysis reaction, not a condensation reaction.

Option D, a polymer is broken down into monomers and a water molecule is used up, is also a hydrolysis reaction, not a condensation reaction.

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Answer:

https://clever.com/

Explanation:

The  reaction would a decrease in container volume cause the equilibrium to shift to the left is  N₂(g) + 3H(g) ? 2 NH₃(g).

The equilibrium constant (K) expresses the ratio of the concentrations of the products to the concentrations of the reactants at equilibrium. If K is greater than 1, then the equilibrium lies toward the products; if K is less than 1, then the equilibrium lies toward the reactants. Therefore, the reaction that would shift to the left upon a decrease in container volume is the one with K less than 1.

In this case, the reaction with K less than 1 is N₂(g) + 3H₂(g) ? 2 NH₃(g). This is because there are four moles of gas on the left-hand side and only two on the right-hand side. When the container volume is decreased, the pressure increases, which favors the side with fewer moles of gas.

Therefore, the equilibrium shifts to the left to decrease the pressure.

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Answer:

It takes 86 days take to cover half of the lake

Explanation:

In the day #1, the amount of the algae is X,

In the day #2 is 2X

In the day #3 is 2*2*X = X*2²

...

In the day #n the amount of the algae is X*2^(n-1)

Assuming X = 1m³. In the day 87, the area infected was:

1m³*2^(87-1)

7.74x10²⁵m³ is the total area of the lake

the half of this amount is 3.87x10²⁵m³

The time transcurred is:

3.87x10²⁵m³ = 1m³*2^(n-1)

Multiplying for 5 in each side:

ln (3.87x10²⁵) = ln (2^(n-1))

58.9175 = n-1 * 0.6931

85 = n-1

86 = n

Explanation:

See the table above. Periods at the side, metals at the top, non metals to the right, group to the right of that

USC's wood-chip gasification plant generates methane, a clean, renewable energy source, using organic waste like wood chips. This waste-to-energy technology generates syngas, which can be used for electricity and heat, and methanation increases its methane content to 95%.

The methane generated by USC's wood-chip gasification plant is a clean and renewable source of energy. Wood-chip gasification is a type of waste-to-energy technology that uses organic waste, such as wood chips, as fuel to generate electricity, heat, and other forms of energy.

The process involves heating the wood chips in an oxygen-limited environment to produce a gas that is primarily composed of carbon monoxide, hydrogen, and methane. This gas, called syngas, can be used as a fuel to generate electricity and heat.Syngas can be converted into methane through a process called methanation. This process involves adding hydrogen to the syngas, which reacts with the carbon monoxide to produce methane. Methanation can increase the methane content of syngas to around 95%, making it a high-quality fuel that can be used in a variety of applications.

The methane generated by USC's wood-chip gasification plant is a renewable source of energy because it is produced from organic waste that would otherwise be discarded. This means that the plant can generate energy without contributing to the depletion of finite resources such as fossil fuels. Additionally, the use of methane as a fuel produces fewer emissions than traditional fossil fuels, making it a cleaner energy source.

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Answer:

you did not give the specific heat like formula like it takes 1kj to raise 28grams of water by 10 grams

True. The reaction of sodium metal with water to form sodium hydroxide and hydrogen gas is highly exothermic, releasing a large amount of energy.

This reaction is also highly spontaneous, as it has a negative Gibbs free energy change (ΔG).

The spontaneity of the reaction can be explained by the fact that sodium metal has a lower electronegativity than hydrogen or oxygen, so it has a strong tendency to donate its electrons to these atoms to form stable ionic compounds.

The reaction also benefits from the increase in entropy that occurs as the solid sodium metal and liquid water are converted into the aqueous sodium hydroxide and gaseous hydrogen, increasing the disorder of the system.

Overall, the reaction is highly exothermic and spontaneous, making it a useful and commonly used method for producing hydrogen gas.

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The concentration of NO3-N in mg/L = 10 mg/L.

The given water sample contains 10 mg NO3/L.

To find the concentration of NO3 in millimoles/L:

1 mg = 1/1000 g1 mole of NO3 contains 1 + 3x16 = 61 g NO3So, 1 g NO3 = 1/61 mole NO3

Thus, 10 mg NO3 contains (10/1000) * (1/61) mole of NO3= 0.000163934426 mole of NO3

Therefore, the concentration of NO3 in millimoles/L = 0.000163934426 * 1000= 0.163934426 millimoles/L

To find the concentration of NO3-N in mg/L:1 mole of NO3 contains 1 mole of N= 14 g N

Thus, 1 g NO3-N = 1/14 mole of NO3-N

Therefore, 10 mg NO3-N contains (10/1000) * (1/14) mole of NO3-N= 0.000714285714 mol of NO3-N

Therefore, the concentration of NO3-N in mg/L = 0.000714285714 * 14000= 10 mg/L.

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To convert from nanocoulombs to coulombs, divide the number of nanocoulombs by 10^9.

The conversion between nanocoulombs (nC) and coulombs (C) is based on the fact that 1 coulomb is equal to 10^9 (1 billion) nanocoulombs.

Conversely, to convert from coulombs to nanocoulombs, multiply the number of coulombs by 10^9. For example, if you have 0.5 coulombs, this is equal to 0.5 x 10^9 = 500,000,000 nanocoulombs.

The coulomb is the standard unit of electric charge in the International System of Units (SI), and is used to measure the amount of electric charge in a system. The nanocoulomb is a subunit of the coulomb, and is used to measure small amounts of electric charge.

Conversion between nanocoulombs and coulombs is important in many areas of physics and engineering, including electricity, electronics, and electrical engineering. Understanding the relationship between these units and being able to accurately convert between them is critical for accurate and precise measurement and calculation.

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