Potassium-40 decays into other elements wth a half half of 1.25 billion years. A geologist calculates a rock to be 2.50 billion years old. The rock contains 98.4 g of potassium-40. How much potassium-40 was initially in the rock?

Volume of hydrogen could be produced from 256g of glucose at STP is 381.69 L.

The balanced reaction is given as :

C₆H₁₂O₆  +  6H₂O  ---->   12H₂   +   6CO₂

moles of H₂ = 12 mol

mass of glucose = 256 g

moles of glucose = mass / molar

                             = 256 / 180.16

                             = 1.42 mol

1 mole of glucose = 12 mole of H₂

1.42 moles = 12 × 1.42 = 17.04 mol

1 mole of an ideal gas at STP is 22.4 L

volume = 17.04 × 22.4 = 381.69 L

Thus, Generating hydrogen from water or methane is energy intensive. A non-natural enzymatic process has been developed that produces12 moles of hydrogen per mole of glucose by the reaction. Volume of hydrogen could be produced from 256g of glucose at STP is 381.69 L.

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The foreign substance responsible for causing an allergic reaction is called an allergen.

The exaggerated reaction of our body’s immune system to certain foreign substances is known as an allergy.

The symptoms of allergy are sneezing, watery eyes, running nose, and difficulty in breathing which occur due to the release of certain chemicals like histamine and serotonin in our body.

The foreign substance that causes allergy is called an allergen.

Common examples of the allergens are pollen grains of certain plants, animal dander, and food items like peanuts, mushrooms etc.

To control the symptoms of allergy, drugs like antihistamines and steroids are used.

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A polymer mixture p that has number-average and weight-average molecular weights of 120,000 and 300,000 and then Number average molecular weight is 110,000 g/mol

a) The number average molecular weight (NAM) is calculate using the mole numbers of each component. In this case, we will multiple each component molecular weight by the number of moles of each one. After that we will sum them and finally to divide by the total number of moles.

NAM = (Na*MA + Nb*MB)/(Nt)

NAM = (1 mol *120000 g/mol + 1*100000 g/mol ) /(2 mol)

NAM = 110000 g/mol

The number average molecular weight for the polymer P is 110,000 g/mol

We have a polymer P made up of two monodisperse fractions.

A with molecular weight of MA = 120000 g/mol and B with MB =100000 g/mol.  

The batch contains an equal mole fraction of each component A and B.  

Let's suppose a total number (Nt) of mols 2 moles. Equal fraction means XA = 0.5 and XB =0.5

Nt = 2 mol

Na = 2*0.5 = 1 mol

Nb = 2*0.5 = 1 mol.

So, we have 1 mol of A, 1 mol of B and 2 moles in total.  

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The relationship demonstrated is the orbit of the Earth around the Sun. The ball represents the Sun and the string represents the gravitational force that keeps the Earth in its elliptical path around the Sun.

Relationship building is the process of establishing and maintaining relationships with people from and outside your network. Usually, people aim to build relationships with those who can help them achieve their goals or will support their mission.

Having strong relationship-building skills also means being able to approach and connect with others while keeping an open mind when communication difficulties arise.

Furthermore, it requires strong networking and teamwork skills, as they are necessary for all types of interpersonal communication.

And because relationship-building is considered a soft skill, we advise you to abstain from listing it in your resume’s skills’ section. Instead, show attention to detail and prove you’re a confident communicator who’s always up for a challenge.

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3a. The mass concentration of H2O in the air when mole fraction of water in the air is 2 percent at P=1 atm at 15 ∘C is 13.5 g/m³.

3b. The mass concentration of oxygen atoms in this gas is 1909.85 μg/m³.

3a. Given: Mole fraction of water in the air = 2%

Pressure, P = 1 atm

Temperature, T = 15 ∘C

We can find the mass concentration of H2O using the formula:

mass concentration = (partial pressure of H2O) / (RT) x MW x 1000

Where, R = 0.0821 L atm mol-1 K-1

T = 15 + 273 = 288 KMW of H2O = 18 g/mol

The partial pressure of H2O can be calculated using Dalton's law of partial pressure:

P H2O = mole fraction of H2O x total pressure

= 0.02 x 1 atm

= 0.02 atm

Substitute the values into the mass concentration equation:

mass concentration = (0.02 atm) / (0.0821 L atm mol-1 K-1 × 288 K) × (18 g/mol) × 1000

= 13.5 g/m³

Therefore, the mass concentration of H2O in the air when mole fraction of water in the air is 2 percent at P=1 atm at 15 ∘C is 13.5 g/m³.

3b. Given:

Pressure, P = 1 atm

Temperature, T = 15 ∘C

We need to find the mass concentration of oxygen atoms in this gas. For this, we first need to find the mole fraction of oxygen. We can use the following formula:

mole fraction of oxygen = 1 - (mole fraction of water + mole fraction of other gases)

Mole fraction of water = 2/100 = 0.02

Mole fraction of other gases = 1 - mole fraction of water

= 1 - 0.02

= 0.98

At standard conditions, 1 mole of gas occupies 22.4 L.

But at given conditions (P=1 atm and T=15 ∘C),

the volume occupied by 1 mole of gas can be found using the following equation:

PV = nRTV = (nRT) / PM

where, V = volume of 1 mole of gas

n = number of moles of gas

R = universal gas constant = 0.0821 L atm mol-1 K-1

T = 15 + 273 = 288 K

Now, we can find the number of moles of oxygen atoms using the following formula:

number of moles of oxygen atoms = (mass concentration of other gases) / (MO of O2)

Where, MO of O2 = 32 g/mol

Now, we can calculate the mass concentration of oxygen atoms using the following formula:

mass concentration of oxygen atoms = (number of moles of oxygen atoms) × (MO of O2) × (1000 μg/mg) / (volume of 1 mole of gas)

Substitute the values into the above equations:

V = (1 × 0.0821 × 288) / 1

= 23.74 L/mol

Number of moles of oxygen atoms = (0.98) / (32 g/mol)

= 0.030625 mol

Mass concentration of oxygen atoms = (0.030625 mol) × (32 g/mol) × (1000 μg/mg) / (23.74 L/mol)

= 1909.85 μg/m³

Therefore, the mass concentration of oxygen atoms in this gas is 1909.85 μg/m³.

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In the event that the SIM (Sulfide Indole Motility) medium is utilized entirely for testing motility and indole generation, the ingredients that can be killed are those particularly related to the discovery of hydrogen sulfide (H2S) generation. These ingredients incorporate ferrous sulfate or ferrous ammonium sulfate, which are utilized to identify the arrangement of dark precipitates showing the presence of H2S.

In the event that the testing is exclusively for motility and sulfur reduction, the ingredients that can be killed are those related to the discovery of indole generation. Indole isn't directly included in sulfur reduction, so the following fixing can be removed:

Bacteria have the enzymes vital to utilize citrate as a source of vitality and carbon, but not all microbes can develop on citrate media. The failure of a few microbes to develop on citrate media can be clarified by the taking after reasons:

It's vital to note that the capacity to develop on citrate media is regularly evaluated utilizing the Simmons citrate agar test, which contains sodium citrate as the sole source of carbon.

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Answer:

B! SPIRAL CAUSE ITS SPINNY AND PRETTY UWUUUUUU hehe :3

Answer:

The net reaction is Zn(s) + 2H +(aq) → Zn2+(aq) +H 2(g) The Cl− ions are spectators - they don't change. This experiment includes the reaction of zinc with hydrochloric acid.

Answer:

Explanation:

An object is thrown vertically from the ground upwards with a speed of 10 m/s. Considering g = 10 m/s2, the maximum height that the object reaches from the ground, in meters, will be:

a) 15.0.

b) 10.0.

c) 5.0.

d) 1.0.

e) 0.5.

Answer: The destruction of crust occurs at deep-sea trenches. Oceanic rocks are pillow-shaped when formed. Rocks across the ocean floor have alternating magnetic stripes. Younger rocks are closer to mid-ocean ridges.

Answer:

72.58 g/mol

Explanation:

mark me brainless if I am ✅

The relationship between the rate of diffusion and the molar mass is given by Graham's law.  A gas diffusing 1/6 times faster than hydrogen will have a molar mass of 72.58 g/mol. Thus, option d is correct.

Graham's law states the inverse relationship between the rate of diffusion and the square root of the molar mass of the gas. It is given as,

Rate = 1 ÷ √M

The molar mass of the gas that diffuses 1/6 times faster than hydrogen is calculated as,

R₁ ÷ R₂ = √ (M₂ ÷ M₁)

Here,

The molar mass of hydrogen = M₁

The molar mass of unknown gas = M₂

Rate of diffusion of hydrogen gas = R₁

Rate of diffusion of unknown gas = R₂ = 1 / 6 R₁

Substituting values:

R₁ ÷ 1/6 R₁ = √M₂ ÷ 2

6 × 1.414

= 8.485

= 84.85 g/mol ≈ 72.58 g/mol

Therefore, option d. 72.58 g/mol is the molar mass of unkown gas.

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Lead + Iron(II) Sulfate = Lead Sulfate + Iron

Lead - Pb

Plumbum Element 82 Bulk Lead 鉛 Lead (native) Lead-210 Pb-210 210Pb

Iron(II) Sulfate - FeSO4

Iron Sulfate (1:1) Iron(II) Sulfate (1:1) Ferrous Sulfate (anhydrous) Ferrous Sulfate Ferrous Sulfate (anh.) Iron(2+) Sulfate (anh.) FeSO4 Fe(II)SO4

Lead Sulfate - PbSO4

Anglesite

iron - Fe

Element 26 Fer 26Fe Eisen Ferrum Hierro Ferrum Metallicum 鐵

True. An alloy is a solid solution consisting of two or more metallic elements, or a metallic element and a non-metallic element.

The properties of an alloy are usually different from those of its constituent elements. The reason for this is that the atoms of different elements in an alloy interact with each other differently than they would if they were in their pure elemental form. This interaction can lead to changes in the electronic and crystal structure of the alloy, which in turn can affect its physical and chemical properties. Some common examples of alloys include brass (copper and zinc), stainless steel (iron, chromium, and nickel), and bronze (copper and tin).

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Complete question:

An alloy is a mixture of elements that has metallic properties. True or False

P stands for pressure and is 1.89 103 kPa. This is equivalent to 1.89 x 10310.325 x 18.65 atm.

Thus, the value of $gamma $ is 1.664 for molecular formula gas such the precious gases He, Ne, or Ar and = 1.4 for diatomic gases, etc. The number of moles is n, while R is really the gas standard. As a result, 0.7L of 5.6L of argon gas at the STP is obtained by adiabatic compression.

An molecule of something like the chlorine atom helium as known as a helium atom. Hydrogen is made up of two electrons connected either by electromagnetism toward a structure comprising two protons and either one or 2 particles, based on the isotope, bound together through a strong force.

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Answer:

Explanation:

The absorbed sunlight drives photosynthesis, fuels evaporation, melts snow and ice, and warms the Earth system. Solar power drives Earth's climate. Energy from the Sun heats the surface, warms the atmosphere, and powers the ocean currents.

Answer:

I think C is the most reasonable answer

a) The reactant that is totally consumed throughout the reaction is the limiting reactant.  We must compare the quantity of moles of each reactant present to their stoichiometric coefficients in the balanced equation to identify which chemical is the limiting reactant.

Using their respective molar , we must translate the masses of \(Al\) and \(Br2\)  into moles in this situation:

\(10.0 g / 26.98 g/mol\)  of aluminium equals 0.370 mol.

mol \(Br2\)  is equal to \(15.0 g/159.81 g/mol,\) or 0.094 mol.

The balanced equation shows that Al and \(Br2\) have a stoichiometric ratio of 2:3. As a result, 3 moles of \(Br2\) are needed for every 2 moles of Al that is consumed. \(Br2\) is the limiting reactant because we don't have as much of it as the stoichiometry dictates.

b) The unutilized portion of the reactant remains after the reaction is complete. Since some Al is still present after all of the \(Br2\)has been burned, Al is the surplus reactant in this instance.

c) By looking at the equation in balance, we can see that 2 moles of Al and 3 moles of \(Br2\) combine to form 2 moles of \(AlBr3\) . Having established that \(Br2\) is the limiting reactant, we can utilise its mole quantity to determine the number of moles of \(AlBr3\) that are generated:

mol \(AlBr3 = 0.094\)  mol \(Br2\) , where \((2 mol AlBr3 / 3 mol Br2)\)  results in a mol \(AlBr3 of 0.063.\)

As a result, 0.063 mol of \(AlBr3\)  are created.

d) If the limiting reactant (\(Br2\)) is completely used, we can determine how much extra reactant is there.  Applying the balanced equation's stoichiometry, there is still (Al) left over. 2 moles of Al are used for every 3 moles of \(Br2\) . We can calculate how much Al was burned by using the mole quantity of \(Br2\), since we know that all of the Br2 has been used:

mol Al burned equals 0.094 mol \(Br2\) ; 2 mol Al divided by 3 mol Br2 equals 0.063 mol Al.

Thus, the quantity of Al that is still present is:

mol of Al left = 0.370 mol of Al - 0.063 mol of Al = 0.307 mol of Al (Answer in 25 words: 0.307 mol Al remains when all the Br2 is consumed.)

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the density of gases in the thermosphere to the density at sea level is The atmosphere is 10 times denser at sea level.

Air density decreases with height. There are two reasons for this: higher altitudes have very little air pressing down from the above, and gravitationally is weaker farther away from the Earth's centre. As a result, at higher elevations, air molecules can scattered out more, resulting in a reduction in air density. Heavier gas will drop, while lighter air will rise. Because the compression caused by the mass of air above it, air at water level is denser. The quantity of gas molecules in the air reduces as altitude increases—the air becomes less tightly packed closer to sea level. This is what weathermen and mountaineers mean when they talk about "thin air." Thin air exerts less push than lower-altitude air.

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The liquid property which occurs when molecules are weakly attracted to one another, allowing the molecules to move easily from the liquid to the gas phase is volatility and is denoted as option C.

This is referred to as a term which is used to describe how easily a substance will vaporize and this means how fast it turns into a gas or vapor under normal conditions.

This is usually due to the molecules being weakly attracted to one another which allows them to move easily from the liquid to the gas phase and is therefore the reason why it was chosen as the correct choice.

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Answer:Volality

Explanation:

Answer 12.2g is the answer

Answer:

a

Explanation:

because

Answer:

A.) Compounds cannot be broken down into simpler substances by chemical means.

Explanation:

just took test on e2020 :)

Burrows, tracks, coprolites, nests and footprints are examples of traces that can be found in a fossil.

Answer:

yes

Explanation:

Among the options listed, frost wedging is not directly related to chemical weathering.

Frost wedging is a physical weathering process that occurs in cold climates where water seeps into cracks in rocks, freezes, and expands, exerting pressure on the surrounding rock.

This expansion can cause the rock to break apart over time. While frost wedging does involve the action of water, it does not involve chemical reactions.

On the other hand, the remaining options—hydrolysis, oxidation, and decomposition—are all forms of chemical weathering. Hydrolysis is a chemical reaction where water molecules react with minerals in rocks, leading to their breakdown or alteration.

Oxidation occurs when oxygen reacts with certain minerals, such as iron, in rocks, resulting in their rusting or decomposition. Decomposition, also known as biological weathering, involves the breakdown of rocks through the actions of living organisms, such as lichens and plant roots.

Chemical weathering processes, including hydrolysis, oxidation, and decomposition, can alter the chemical composition and structure of rocks over time.

These processes play significant roles in shaping Earth's surface by breaking down and transforming various rock types.

Frost wedging, although a powerful physical weathering process, is not classified as a chemical process as it does not involve chemical reactions or changes in the mineral composition of rocks.

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The acidity of constitutional isomers of the compound 6 CI OH 12 CI can be altered by changing the functional group attached to the carbon atom.

An additional methyl group can make the molecule more acidic, a hydroxyl group can make it slightly less acidic, and an ethyl alcohol group can make it significantly less acidic.

A constitutional isomer is a molecule with the same molecular formula as another molecule, but with a different arrangement of atoms in space.

The compound shown in the question is composed of 6 carbon atoms and 12 hydrogen atoms, arranged in the form of 6 CI OH 12 CI. This compound has many constitutional isomers that differ in their acidity.

(a) One constitutional isomer that is slightly more acidic than the compound in the question is 6 CI CH3 OCH3 12 CI. This isomer has an additional methyl group, which can serve as a proton acceptor to increase the acidity.

(b) Another constitutional isomer that is slightly less acidic is 6 CI CH2OH 12 CI. This isomer has a hydroxyl group instead of the methyl group, which can serve as a proton donor to decrease the acidity.

(c) Finally, one constitutional isomer that is significantly less acidic is 6 CI CH2CH2OH 12 CI.

This isomer has an ethyl alcohol group instead of a methyl or hydroxyl group, which can serve as a stronger proton donor to further decrease the acidity.

In conclusion, the acidity of constitutional isomers of the compound 6 CI OH 12 CI can be altered by changing the functional group attached to the carbon atom.

An additional methyl group can make the molecule more acidic, a hydroxyl group can make it slightly less acidic, and an ethyl alcohol group can make it significantly less acidic.

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Answer:

72kg

Explanation:

mass does not change with gravity but weight would :)

The answer is Science.

What is the investigation and exploration of natural events and of the new information that results from those investigations is Science.

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Answer:

69%

Explanation:

Percent yield = ?

Theoretical yield = 985 grams

Experimental Yield = 680 grams

Percent Yield = Experimental Yield / Theoretical Yield * 100

Percent Yield = 680 / 985  * 1 00

Percent Yield = 0.690 * 100 = 69%