how can you tell if an substance is an elements
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The proportion of exams scores between 68 and 73 points is 38.09%.

We must first determine the z-score for both points.

The z-score formula is:

Z-score is equal to (x-mean)/SD.

Given that in this instance:

Mean = 70

SD = 5

So, for a 68-point exam grade:

(68 - 70) / 5 is the z-score.

= –2 / 5

= –0.4

And for a 73 point exam grade:

(73 - 70) / 5 is the z-score.

= 3 / 5

= 0.6

Thus, the likelihood:

P (68 < x < 73) = P (–0.4 < z < 0.6)

Through the z-table:

P (–0.4 < z < 0.6)

= (0.5 – 0.3446) + (0.7258 – 0.5) (0.7258 – 0.5)

= 0.3809

= 38.09%

As a result, 38.09% of exam scores fall between 68 and 73 points.

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As nac2h3o2(s) is stirred into water and dissolves, the electrical conductivity of the solution remains the same.

The ability of an aqueous solution to convey an electrical current is gauged by its conductivity. Since ions are responsible for carrying the current, the conductivity rises as ion concentration, mobility, and water temperature rise in a solution. Ionic strength is connected to conductivity measurements. But this isn't a qualitative experiment (that is, it is not known which ions are present). The electrical calculation for resistance, which is stated in, is the opposite of conductivity

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The correct answer is 107.9 g of Ag is produced from a reaction of 31. 75 gram of Copper.

Molar mass of a substance is the mass in grams of one mole of the compound. A mole is the measurement of the number of things, such as atoms, molecules, and ions, that are present in a substance. Any material has 6.022 x 1023 molecules in a mole, it is known as Avogadro's number . The mole is used to determine the size of the tiniest entities quantitatively, just as we use a standard value to quantify many things, such as 1 dozen = 12 items.

Formula - Molar mass = mass in grams/mole = g/mol

Molar mass of a substance can be calculated as:

Given,

n = W/M, where

W = required mass

M= molar mas

Given chemical reaction is:

Cu + 2AgNO₃ → Cu(NO₃)₂ + 2Ag

From the stoichiometry of the reaction,

1 mole of Cu = produce 2 moles of Ag

Given mass of Cu = 31.75g

Molar mass of Cu = 63.5g/mol

Moles of Cu = 31.75g / 63.5g/mol = 0.5 moles

0.5 moles of Cu = produce 2×0.5 = 1 mole of Ag

Molar mass of Ag = 107.9g/mol

Required mass of Ag = 1mol × 107.9g/mol = 107.9 g

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The compounds can be distinguished via UV spectroscopy by measuring their value.1,3-pentadiene is a type of conjugated compound while 1,4-pentadiene is not conjugated.

This causes the of 1,3-pentadiene to be higher than 1,4-pentadiene allowing us to distinguish between both. Using UV spectroscopy we measure the quantity or amount of light being absorbed by the sample and compare the obtained values. Thus, 1,3-pentadiene and 1,4-pentadiene can be distinguished by comparing their values obtained by UV spectroscopy.

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This transition has a lower energy for conjugated systems like 1,3-cyclohexadiene. Since this transition has a greater energy for unconjugated systems like 1,4-cyclohexadiene, the wavelength is typically too short to be visible.

cyclohexadiene diols are excellent starting materials for the synthesis of complex natural compounds due to their inherent benefits. For the synthesis of polyhydroxylated targets such inositols, cyclitols, and carbohydrates, the diol moiety is the ideal place to start. The chemical compound cyclohexa-1,3-diene has the formula (C2H4)(CH)4. It is a flammable, colourless liquid. It has a 20 °C, D, refractive index of 1.475. Terpinene, a substance found in pine oil, is a 1,3-cyclohexadiene derivative that occurs naturally. Cyclohexane, which has the chemical formula C6H12 and is planar and cyclic, lacks delocalized pi electrons (since there are no pi bonds), and it also does not abide by Huckel's rule. As a result, it lacks fragrance.

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There are 112 oxygen atoms in 5.00 moles of MgSO4. This is because MgSO4 is composed of 1 mole of magnesium (Mg), 1 mole of sulfur (S), and 4 moles of oxygen (O).

What is composed?

Composed is a term used to describe the process of creating something, usually through artistic means. It can be used to refer to writing a song, painting a picture, or composing a poem. It can also refer to the creation of a musical composition or arrangement, either by an individual or as part of a team.

Therefore, if there are 5.00 moles of MgSO4, there would be 4 x 5.00 = 20 moles of oxygen, and since there are 6.02 x 10^23 atoms per mole, there would be 20 x 6.02 x 10^23 = 1.204 x 10^25 oxygen atoms.

Composed can also refer to the arrangement of elements in a piece of art or design, or the overall structure of a work. In some cases, the term may be used to refer to the creative process of planning and assembling a work, such as a book, movie, or painting.

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Answer:

To determine the limiting reactant, you need to compare the amount of each reactant with the amount required to react completely with the other reactant. The reactant that runs out first is the limiting reactant.

In this case, the balanced equation for the reaction between MgSO4 and NH3 is:

MgSO4 + 2 NH3 → Mg(NH2)2SO4

From the balanced equation, we can see that 1 mole of MgSO4 reacts with 2 moles of NH3. Therefore, 3.7 moles of MgSO4 will react with (3.7 moles)(2 moles NH3/1 mole MgSO4) = 7.4 moles of NH3.

4.8 moles of NH3 is less than 7.4 moles, so NH3 is the limiting reactant.

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Fossil fuels may cause water pollution because they release toxicants into the atmosphere, which is formed by air and water.

The relationship between fossil fuels and water pollution is based on the fact that fossil fuels are burned to release energy which may generate contamination that affects water into the atmosphere.

Therefore, with this data, we can see that the relationship between fossil fuels and water pollution is based on the release of toxic substances and greenhouse gases during this process that affects water in the atmosphere.

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By changing gear and according to the brakes applied to the car.

Acceleration is the rate of change of the velocity of an object with respect to time.

There are three types of accelerated motions such as :

Therefore, In a car you could accelerate by hitting the gas or the brakes either of which would cause a change in speed. But you could also use the steering wheel to turn which would change your direction of motion. The car moves faster and faster, speed is the rate of change of position while acceleration is the rate of change of velocity.

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Ionic bonds, also known as electrovalent bonds, are a type of linkage created in a chemical molecule by the electrostatic attraction of ions with opposing charges.

When the valence electrons of one atom are permanently transferred to another atom, a bond of this kind is created. If an atom receives electrons, it becomes a charged ion, but if it loses them, it becomes a positively charged ion.

Ionic or electrovalent compounds are produced via ionic bonding, and the compounds generated between nonmetals and alkali and alkaline-earth metals serve as the best examples of this type of compound.

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the conjugate acid for each base is conjugate acid of H2PO−4 : HPO4^2-, conjugate acid of SO2−4 : HSO4-, conjugate acid of NH3 : NH4+

A conjugate acid-base pair is a pair of substances that differ by only a proton. An acid is a substance that donates a proton (H+) in a chemical reaction, while a base is a substance that accepts a proton. When an acid loses a proton, it becomes its conjugate base, and when a base gains a proton, it becomes its conjugate acid.For example, the conjugate acid of the base NH3 is NH4+ and the conjugate acid of the base H2O is H3O+. The conjugate acid and the base are in equilibrium with each other, and the acidity constant (pKb) of the base is related to the basicity constant (pKa) of the conjugate acid. In acid-base reactions, the acid donates a proton to form its conjugate base, and the base accepts a proton to form its conjugate acid.

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When a solution is acidic, its pH will vary from 0 to 6.9. The pH of a basic solution may range from 7.1 to 14. When a solution is neutral, its pH will be 7.

A solution is a uniform mixture made up of two or more elements that have particles smaller than one nanometer. There are many different types of solutions, such as soda water, salt-and-sugar solutions, and others. A solution looks to have one phase for each component.

A solution in chemistry is a mixture of several substances in quantities that can be adjusted up to

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The air pressure at the top of Mount Everest in atmospheres is equal to 0.2618 atm.

In Science, pressure can be defined as a measure of the force exerted per unit area of an object or physical body. This ultimately implies that, pressure is usually measured in Newton per meter square and calculated by using this formula:

P = F/A

Where:

Generally speaking, air pressure can be measured in other units such as the following:

In order to convert the value of pressure in millimeters of mercury (mm Hg) to atmosphere, we would divide by 760 as follows:

Air pressure = 199/760

Air pressure = 0.2618 atm.

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Answer: 0.261842

Explanation:

The lower boiling point of propane  makes it better in winter compared to butane.

The term LPG stands for liquified petroleum gases. It is one of the kinds of the gases that we can be able to use as fuel. We have to know that the gases that are used as fuel are the gases that are able to burn very well as this is key in the use of the fuel.

In the winter, we would need to use a gas that has a much lower boiling point and this is why in this case, the propane would be found to be better than butane due to its lower boiling point.

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Answer:

14.5 moles of CH4

Explanation:

There is 14.5 moles of carbon in the product CO2....there has to be 14.5 moles of carbon in the reactant CH4

   14.5 moles

When pipes leak, the environment's air, water, soil, and climate might be harmed. When there is a lot of rain and flooding, pipes that span rivers and streams are more likely to burst.

Acid rain, deteriorating water quality, groundwater contamination, and the greenhouse effect's intensification are only a few significant environmental effects. Aside from destroying ecosystems that, in some cases, may be unique, the oil and gas industry may also be a factor in the decline of biodiversity. Drilling and milling machines have both advantages and drawbacks.

Benefits: accurate points, good feed control, and challenging to roll. Retraction's shortcomings include its lack of flexibility and inability to process large or deep holes. Furthermore, methane, a greenhouse gas 21 times more potent than carbon dioxide, is released in enormous quantities by the oil and gas sector. In total, the industry is to blame for 3.8% of all greenhouse gases, or 38% of all methane emissions in the United States.

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The mole fraction of LiBr is 0.8946

We are aware that the mole fraction or molar fraction is defined as the amount of a constituent (expressed in moles), ni, divided by the total amount of all the elements in the mixture (also indicated in moles, ntotal).

mole fraction = n/n overall

first we should calculate hw many gram the solution from the density

assume the volume is 1 L

so.

density = mass solution/ volume solvent

0.826 g/ml = mass/ 100mL

mass= 82.6 g

so the mole of the solution is

mole = mass/ mass molar

mole solution = 82.6 g / 41.05g/ mole = 2.012 mole

Then we can find the mole of LiBr from the concentration

molar= moles x volume

1.8 M = moles x 1 L

moles LiBr = 1.8 moles

thus,

mole fraction = n/ n total

mole fraction = 1.8/  2.012 =  0.8946

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The resulting empirical formula is Na2CrO4.

The empirical formula of a compound is the simplest whole-number ratio of the elements it contains. To calculate the empirical formula, we must first determine the molar ratio of the elements by dividing their masses by their respective molar masses.

For sodium, the molar mass is 22.99 g/mol. Therefore, the molar ratio of sodium is 29.84 g / 22.99 g/mol = 1.30 mol.
For chromium, the molar mass is 51.99 g/mol. Therefore, the molar ratio of chromium is 39.7 g / 51.99 g/mol = 0.76 mol.
For oxygen, the molar mass is 16.00 g/mol. Therefore, the molar ratio of oxygen is 72.67 g / 16.00 g/mol = 4.54 mol.
To get the empirical formula, we must divide each of the molar ratios by the smallest molar ratio, which in this case is 0.76 (for chromium). The resulting empirical formula is Na2CrO4.

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The absolute configuration of any of the amino acid is :

             H                                     H

              |                                        |

HOOC - C - NH₂                  H₂N - C - COOH

              |                                        |

            CH₃                                   CH₃

The configuration of the amino acid is indicated by the pointing H at the rear, the R group is in the right direction , The COOH group is in the left direction and the NH₃ group in the upward direction.

             H                                     H

              |                                        |

HOOC - C - NH₂                  H₂N - C - COOH

              |                                        |

            CH₃                                   CH₃

D - amino acid                      L - amino acid

The proteins which are naturally obtained are consist of the L - amino acid.  The L - of the amino acid are the one that found in the nature easily.

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As an animal grows, its mass increases. The matter that makes up this new mass comes mostly from the food  that the animal consumes.

Matter in chemistry, is defined as any kind of substance that has mass and occupies space that means it has volume .Matter is composed up of atoms which may or not be of same type.

Atoms are further made up of sub atomic particles which are the protons ,neutrons and the electrons .The matter can exist in various states such as solids, liquids and gases depending on the conditions of temperature and pressure.

The states of matter are inter convertible into each other by changing the parameters of temperature and pressure.

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When 445 kilograms of water are reacted, 102.94 or 103 grams of MnO2 mass are formed.

A bodily lump is referred to in medicine. It could be brought on by an immunological response, a cyst, hormonal abnormalities, or aberrant cell growth. A mass could either be benign (not cancerous) or malignant (cancer).

Simply said, mass is a method of determining that however much material seems to be present in something like a body. Matter is anything with both weight and volume.

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Answer: 4,300 g

Explanation:

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The independent variable here is the distance water traveled out of the carton.

The factors of the subject or the things that have an impact on the experiment are known as the variables of an experiment. Three different sorts of variables exist. These variables are control, independent, and dependent.

Independent variables are ones that are not under the experimenter's direct control. The experimenter can alter or regulate the dependent variables. Control variables are those that don't change or are constrained during the experiment.

The carbon's journey distance is the dependent variable in this situation when Mario studied how far room temperature water would spurt out of a plastic milk carton when 3mm holes were punched at different heights from the bottom of the container.

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Answer:

This answer makes an assumption noted in the Explanation.

1.772 moles of NO2

Explanation:

The balanced equation tells us that NO2 does not react with N2O5.  As written, the answer to the question is zero.

If the question is how many moles of NO2 are produced by 0.8861 moles of N2O5, then we can note that the equation promises us 4 moles NO2 per 2 moles N2O5.  That's a molar ratio of 4:2 (moles NO2/moles N2O5).

(0.8861 moles N2O5)*(4:2 (moles NO2/moles N2O5)) = 1.772 moles of NO2

Involves the reduction of one molecule CuI+e to Cu and the oxidation of another CuI to CuII+e. A different illustration of a disproportionation reaction is the interaction of halogens with hydroxide ions, such as Cl2(g)+2OH(aq) Cl(aq)+ClO(aq)+H2O(l).

One mole of aluminium weighs 26.982 g, which may be found on the periodic table to determine the atomic mass and the number of grammes per mole.

The chemical name for aluminium is Al. 26.98 g/mol is the molar mass. The elemental form of metallic aluminium is present (the most fundamental form is the elemental form, which is expressed in the periodic table). We can use the formula 2(n2) because the atomic number of aluminium is 13.

Reaction to displacement This reaction is a synthesis since it involves the combination of two reactants (Al and O2) to produce a single product, Al2O3. Utilize all of the digits associated with the atomic weights as listed on their periodic table. Use the resulting molar mass after adding them all up. Avoid rounding the molar mass.

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Isopentane, commonly known as methyl butane or 2-methylbutane, is an alkane with a branched chain and five carbon atoms. Its chemical formula is C 5H 12 or CH(CH).

At normal temperature and pressure, isopentane is a highly flammable and volatile liquid. Additionally, under normal circumstances, it is the least dense liquid. [Reference needed] Isopentane has a standard boiling point that is only a few degrees above room temperature, therefore on a warm day, it will easily boil and evaporate. To achieve a liquid bath temperature of 160 °C, isopentane and liquid nitrogen are frequently utilized. Isopentane is a substantial component of natural gasoline, however, it normally only makes up 1% or less of natural gas.

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Answer:

The sun is it's darkened phase

Answer:

A substance with particular chemical properties including turning litmus red, neutralizing alkalis, and dissolving some metals; typically, a corrosive or sour-tasting liquid of this kind. Often contrasted with alkali and base.

The highest pH is 1

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Potential Energy stored in bond of molecules is called chemical energy.

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Since there are 6.022 1023 molecules in 1 mole of oxygen (O2), it has a mass of 32 grams.

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The amount of negative charge in one mole of oxygen gas, [tex]O_{2}[/tex] is 9.647 x [tex]10^{14}[/tex] coulomb.

One mole of oxygen gas, with the formula O2, weighs 32 g and includes 6.02 x [tex]10^{23}[/tex] molecules of oxygen, but also contains 12.04 x [tex]10^{23}[/tex] (2 x 6.02 x [tex]10^{23}[/tex]) atoms of oxygen, since each molecule of oxygen contains two oxygen atoms.

Since there are 6.022 1023 molecules in 1 mole of oxygen ([tex]O_{2}[/tex]), it has a mass of 32 grams. One mole of oxygen weighs 15.998 grams, whereas one mole of hydrogen weighs 1.008 grams. Since there are 6.022 1023 molecules in 1 mole of oxygen ([tex]O_{2}[/tex]), it has a mass of 32 grams.      

Mass of 1 mole of electrons:

9.10 x [tex]10^{13}[/tex] × 6.023× [tex]10^{23}[/tex] 5.486× [tex]10^{-7}[/tex] kg

Charge of 1 mole of electrons:

1.602× [tex]10^{-19}[/tex] × 6.023× [tex]10^{23}[/tex] = 9.647× [tex]10^{4}[/tex] coulomb

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Answer: F

Explanation: