The United States uses many different energy sources and technologies to generate electricity. The sources and technologies have changed over time, and some are used more than others.
The three major categories of energy for electricity generation are fossil fuels (coal, natural gas, and petroleum), nuclear energy, and renewable energy sources. Most electricity is generated with steam turbines using fossil fuels, nuclear, biomass, geothermal, and solar thermal energy. Other major electricity generation technologies include gas turbines, hydro turbines, wind turbines, and solar photovoltaics.
Natural gas was the largest source—about 38%—of U.S. electricity generation in 2021. Natural gas is used in steam turbines and gas turbines to generate electricity.
Coal was the second-largest energy source for U.S. electricity generation in 2021—about 22%. Nearly all coal-fired power plants use steam turbines. A few coal-fired power plants convert coal to gas for use in a gas turbine to generate electricity.
Petroleum was the source of less than 1% of U.S. electricity generation in 2021. Residual fuel oil and petroleum coke are used in steam turbines. Distillate—or diesel—fuel oil is used in diesel-engine generators. Residual fuel oil and distillates can also be burned in gas turbines.
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how many water (h2o) molecules are in a block of ice that has a mass of 59.5 g? how many atoms of hydrogen are present in this block?
Block of ice of mass 59.5g contains 19.87 ×10²³molecules and 39.75×10²³ atoms.
Molecular mass of Water is 18g/mol
No. of moles = Given mass /Molecular mass
No. of moles of water = 59.5/18 (Given, mass of block of ice is 59.5g)
= 3.3moles.
1mol of water contains 6.023×10²³ molecules of water.
Then,3.3 moles of water contains ,
3.3× 6.023×10²³= 19.87 ×10²³molecules.
1mol of water (H₂O) contains,2× 6.023×10²³ atoms of hydrogen
Then, 3.3 moles of water contains,
2×3.3× 6.023×10²³ = 39.75×10²³ atoms of hydrogen.
Thus, the molecules and atoms present in the block of ice of mass 59.5g is 19.87 ×10²³molecules and 39.75×10²³ atoms respectively.
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What is the major organic product obtained from the following sequence of reaction? nh h2/ni
The catalyst for catalysing the hydrogenation of an unsaturated hydrocarbon is H2/Pt. A saturated hydrocarbon called an alkane, which is the main result, is produced when hydrogen atoms are added across a double or triple bond in the hydrocarbon.
A significant product is what?
The more stable and so more likely to develop main product of a reaction would be. One example would be the electrophilic addition of propane to HBr.
The catalyst for catalysing the hydrogenation of an unsaturated hydrocarbon is H2/Pt. A saturated hydrocarbon called an alkane, which is the main result, is produced when hydrogen atoms are added across a double or triple bond in the hydrocarbon.
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How does water solubility (that is whether it is a polar and therefore hydrophilic or non-polar and therefore hydrophobic molecule) affect signaling molecules?
Water solubility affect signaling molecules because water soluble ligand are polar and therefore cannot pass through plasma membrane
Hydrophobic molecule can diffuse through the plasma membrane and bind to internal receptor water soluble ligand are unable to pass free through the plasma membrane due to their polarity and must bind to an extracellular of the cell. there are so many signals are insoluble in water. signaling molecules are classified in two type hydrophilic and hydrophobic in which hydrophilic signaling molecules are binding to receptors proteins while hydrophobic signaling molecules are transport through bloodstream attached to hydrophilic center.
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question 3 a reaction equation, shown below, consumes 5.0 g of a and 6.0 g of b. how many total grams of c and d should be obtained? 1 a 3 b → 2 c 4 d
By law of conservation of mass The total grams of c and d obtained is equal tp 11 gm
When two or more molecules or compounds interact, one or more new substances are created. These chemical reactions adhere to a set of rules known as the laws of chemical combination. One of the laws of chemical combination is the law of conservation of mass
This law states that the total mass of the reactants equals the total mass of the result in any physical or chemical change (s).
That implies that mass is unaffected by the reaction both before and after it.
Thus, the mass of all reactants equals the mass of all products, and the mass of A and B equals the mass of C and D.
The mass of C and D is (5g + 6g) = 11g
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How will an acetyl functional group behave when placed in an aqueous environment?
How will an acetyl functional group behave when placed in an aqueous environment it will become negatively charged O.
What is aqueous environment?In an aqueous environment, dissolved organic macromolecules that quickly adsorb from the liquid phase will bias a substratum, an inert support surface, in a certain direction. Through a number of different transport processes, bacterial cells in the fluid make contact with the substrate. After reaching the substratum, the cells can adsorb either irreversibly or reversibly.
Adherent cells release extracellular polymers that help them stick tenaciously to the substrate, provided they spend enough time there. Substrates are transported to and within the biofilm, including oxygen, carbon, and nitrogen sources. Attached cells make more insoluble extracellular polymers, primarily polysaccharides, and metabolize the available carbon and energy substrates. They also grow, duplicate, and use electron acceptors as they expand and replicate.
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A negatively charged particle located in the cloud like smear of negative charge of an atom is called a(n)?
A negatively charged particle located in the cloud like smear of negative charge of an atom is called an electron.
The electron (symbol: e⁻) is a subatomic particle whose electric charge is negative one elementary charge.
The electron has a mass that is approximately 1/1836 that of the proton (subatomic particle with a positive electric charge of +1e elementary charge).
An electron cloud is the region of negative charge surrounding an atomic nucleus that is associated with an atomic orbita
The region of negative charge is an electron cloud (high probability of containing electrons). It surrounds an atomic nuclei.
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This graph shows the US unemployment rate from August 2010 to November 2011.
This graph suggests unemployment in the United States
will continue to fall.
will continue to rise.
will remain the same.
This graph suggests unemployment in the United States Will continue to rise.
Governments can buy materials from anywhere. Governments can rely on automation to cut costs. Governments can respond quickly to economic changes. Workers can take internet courses to learn new skills. Automation makes it easier and cheaper to make goods. Companies can hire factory workers anywhere in the world.
It is widely recognized in economics that technology is a key enabler of economic growth in countries, regions, and cities. Prosperity depends on technological advances that allow us to produce more and better goods and services more efficiently. Governments can control income levels by imposing limits on how much their citizens can earn.
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A: will continue to rise
E:
edge 2023
Lialh4 (lah) cannot be used to convert carboxylic acids to the corresponding aldehydes because:______.
LiAlH₄ (LAH) cannot be used to convert carboxylic acids to the corresponding aldehydes because RCOOH is reduced to RCH₂OH.
An organic molecule with the functional group RCH=O is known as an aldehyde. The functional group itself can be categorized as either a formyl group or an aldehyde.
Only when the correct reaction conditions are present in the reaction do specific organic reagents work as intended. For instance, only in the presence of a certain catalyst like Ni or Pt will hydrogen operate as a hydrogenating agent.
Powerful reducing agent LAH (lithium aluminum hydride) is the provided reagent. In the presence of carboxylic acids, it produces equivalent alcohols rather than aldehydes. The conversion of carboxylic acids to their equivalent aldehydes cannot be accomplished using it.
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The complete question is mentioned below:
LiAlH₄ ( LAH ) cannot be used to convert carboxylic acids to the corresponding aldehydes because:
a) LAH is not sufficiently reactive.
b) RCOOH is converted into RCOOLi.
c) RCOOH is reduced to RCH₂OH
d) RCOOH is reduced to RCH₃
e) RCOOH is converted into R₂C = O
The phase changes of many substances are reversible, and a phase change, just like a chemical reaction, may reach providing it takes place in a(n) ________ system.
The answer would be in an equilibrium or closed system.
Because there will be no change in the given chemical reaction. Even if you want to add the catalyst in the given closed system there would be equal amount of sharing in both forward and backward reactions and hence no changing.
Equilibrium can only be acquired in a closed system where the reaction takes place in a closed holder or a vessel and nothing is lost i.e., reactants or products are lost.
So, in conclusion the phase changes in many substances are reversible and a phase change just like a chemical reaction may takes place in an equilibrium, closed system.
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The modern periodic table is organised into groups (columns) and periods (rows). Elements in the same period have similar __________. What completes the sentence?
PLSSS ANSWER
Answer:different numbers of electrons in their valance shells
Explanation:voodoo$
Answer:
the same number of valence electrons
Explanation:
draw the lewis structure for carbon tetrabromide, cbr4. include lone pairs. select the intermolecular forces present between cbr4 molecules
The intermolecular forces present between the molecules of carbon tetrabromide (CBr4) are london dispersion forces.
What are lewis structures?
Dots are used to indicate the positions of electrons surrounding the atoms in a molecule's Lewis structure, and lines or pairs of dots stand in for covalent bonds between atoms. The goal of creating a Lewis dot structure is to locate lone electron pairs in molecules in order to better understand how chemical bonds are formed.
One carbon atom and four bromine atoms make up the chemical compound CBr4, often known as carbon tetrabromide. The carbon atom in the Lewis structure of CBr4 is surrounded by four single bonds, has four bromine atoms connected to it, and has three lone pairs on each of the bromine atoms.
The intermolecular forces present between the molecules of carbon tetrabromide are london dispersion forces.
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magnesium metal, a gray solid, is heated in a crucible in the presence of oxygen. a white powder is collected from the crucible. this is an example of
'Magnesium metals, a gray solid, is heated in a crucible in the presence of oxygen. A white powder is collected from the crucible. This is an example of Chemical change.
What is chemical change?
Chemical change is a process in which any substance or reactant changes or converts into a different product.
The balanced chemical equation of above reaction is :
2Mg(s) + O₂(g) ------Δ-----→ 2MgO
Magnesium metal when heated in a crucible in the presence of oxygen, it forms a white powder of the magnesium oxide.
Magnesium (Mg) gives up two electrons to the oxygen atom to form the white powder. This reaction releases heat and change in enthalpy ΔH° is negative.
A new product, MgO is formed in the reaction having new and different properties and the composition of magnesium also changes.
Burning of magnesium in presence of oxygen is an irreversible change, as magnesium cannot be retrieved from the white powder. All irreversible changes are chemical changes, So this reaction is an example of chemical change.
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If you want to produce 6.83 mol of Al;Os, with how many grams of Al must you start
We must start with 368.82 grams of Al to produce 6.83 mol of [tex]Al_{2} O_{3}[/tex] .
The balanced reaction for the equation as follows:
[tex]4Al + 3O_{2}[/tex] ⇒ [tex]2Al_{2} O_{3}[/tex]
As we can see that 4 moles of Al reacts with 3 moles of [tex]O_{2}[/tex] to produce 2 moles of [tex]Al_{2} O_{3}[/tex], which means 108 grams of Al reacts with 96grams of [tex]O_{2}[/tex] to produce 204 grams of [tex]Al_{2} O_{3}[/tex].
Now,
2 mol of [tex]Al_{2} O_{3}[/tex] react with 108 grams of Al
So,
6.83 mol of [tex]Al_{2} O_{3}[/tex] react with = [tex]\frac{108}{2} *6.83[/tex] grams of Al
6.83 mol of [tex]Al_{2} O_{3}[/tex] react with = 368.82 grams of Al
Therefore, we must start with 368.82 grams of Al to produce 6.83 mol of [tex]Al_{2} O_{3}[/tex] .
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What is the concentration of an aniline solution (c6h5nh2, kb = 3.8 x 10-10) that has a ph of 8.76?
It is a 5.76 m aniline solution .
Mass of the solution = 0.17m
Kb for C6H5NH2 = 3.8 x 10^-10
We know Ka for C6H5NH2 = 1.78x10^-11
We have Kw = Ka x Kb => Ka = Kw / Kb
=> (C2H5NH2)(H3O^+)/(C2H5NH3^+) => 1.78x10^-11 = K^2 / 0.17
K^2 = 3 x 10^-12 => K = 1.73 x 10^-6.
pH = -log(Kw(H3O^+)) = -log(1.73 x 10^-6) = 5.76
What is aniline solution?Organic substance aniline has the chemical formula C6H5NH2. The simplest aromatic amine is aniline, which consists of an amino group joined to a phenyl group. It is an important commodity chemical for industry and a flexible starting point for the synthesis of fine chemicals. The production of colors, industrial chemicals, and precursors to polyurethane are its principal uses. It smells like rotting fish, just like the majority of volatile amines. It easily ignites and burns with the smoky flame that is typical of aromatic chemicals.
In comparison to benzene, it has more electrons. As a result, it takes part in electrophilic aromatic substitution processes more quickly. It is also susceptible to oxidation; fresh aniline is a nearly colorless oil, but exposure to air causes it to gradually turn yellow or red.
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classify each of the properties of ozone (a pollutant in the lower atmosphere but part of a protective shield against uv light in the upper atmosphere) as physical or chemical.
Ozone has a bluish color is a physical property
Ozone has a pungent odor is a physical property
Ozone is very reactive is a chemical property
Ozone decomposes on exposure to ultraviolet light is a chemical property
Ozone is gas at room temperature is a physical property.
What is ozone layer?
We and other living things are protected from the sun's harmful UV radiation by the ozone layer, which is located in the stratosphere between 15 and 30 kilometers above the earth. The ecosystem and human health may suffer significantly if the ozone layer is destroyed.
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A busen burner flame is sooty black and mixed with an organige- yellow color. which is the probable reason for this condition?
The probable reason for busen burner flame this condition insufficient oxygen mixing with gas
Why is that the Bunsen burner flame orange?A gas flame appearing yellow or orange in color or behaving with pops of yellow or orange indicates an improper ratio of oxygen for combustion. Often this improper combustion is temporary and will be caused by dust particles or a dirty burner that needs cleaning.
Why a sooty yellow flame is formed?The yellow/orange/red color is made by carbon soot particles in the flame, produced because the result of incomplete methane gas combustion
Under what conditions does one get a sooty flame?
A black un burned carbon particle are often seen in the sooty flame as this flame burns with a yellow flame due to incomplete combustion.
If there's insufficient air supply, then incomplete combustion of saturated hydrocarbons produces a sooty flame
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A sample of 150 Boron (B) atoms are taken where 120 have a mass of 10 and 30
have a mass of 11. What is the percent abundance of B-10?
A 20%
B 30%
C 10%
D 80%
F 11%
The percentage abundance of B-10 is 80% (Option D)
Data obtained from the questionThe following data were obtained from the question:
Total sample = 150 Amount of B-10 = 120Amount of B-11 = 30Percentage abundance of B-10 =?How to determine the pecentage abundance of B-10The pecentage abundance of B-10 can be obtained as illustrated below:
Percentage abundance of B-10 = (Amount of B-10 / total) × 100
Percentage abundance of B-10 = (120 / 150) × 100
Percentage abundance of B-10 = 0.8 × 100
Percentage abundance of B-10 = 80%
Thus, the percentage abundance of B-10 is 80% (Option D)
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When butter is melted, the _____________ of the butter has changed, but the substance is still butter?
melting of butter is a physical change
Explanation:
the reaction of 1-bromobutane with sodium hydroxide affords the substitution product 1-butanol. what would happen to the rate of the reaction if the concentration of both 1-bromobutane and sodium hydroxide were doubled?
The reaction of 1-bromobutane with sodium hydroxide affords the substitution product 1-butanol the rate increases by a factor of 4.
Option D is correct
Sodium hydroxide: What is it?The homogeneous function idea was developed first for functions with numerous real variables. The concept of vector spaces, which was initially introduced at the end of the 19th century, has naturally been expanded to include functions between vector spaces as a tuple of variable values may be thought of as a coordinate vector.
Usually, there are two definitions used. The general one is applicable to vector spaces across all fields and only enables degrees of homogeneity with integer values.
The second is made to function on an ordered field or, more broadly, a field of real numbers.
Question is incomplete , missing part is given below :The reaction of bromoethane with sodium acetate affords the substitution product methyl acetate. What is the effect of doubling the concentration of sodium acetate on the rate of the reaction?
A) The rate remains the same. C) The rate increases by a factor of 2.
B) The rate decreases by a factor of 2. D) The rate increases by a factor of 4.
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4.2 Rachel measured the mass of an empty 250 cm³ flask. She then filled the flask with a gas of unknown molar mass at an atmospheric pressure of 100 kPa and a temperature of 27 °C. She found that the mass of the flask and contents increased by 0,44 g. a) Calculate the molar mass of the gas Rachel used to fill the flask.
The molar mass of unknown gas at 100kPa pressure and temperature of 27⁰C is 44 gram/mol
According to the ideal gas law, the sum of the absolute temperature of the gas and the universal gas constant is equal to the product of the pressure and volume of one gram of an ideal gas.When applying the gas constant R = 0.082 L.atm/K.mol, pressure, volume, and temperature should all be expressed in units of atmospheres (atm), litres (L), and kelvin (K).Given,
Volume of flask is 250 cm³ or 0.25L
Atmospheric pressure of unknown gas is 100kPa or 0.986 atm.
Temperature is 27⁰C = 27 + 273 = 300K
Increase in mass and content is 0.44gm that means this is mass of unknown gas.
Ideal gas law,
PV = nRT
PV = (m/M)× RT
m is given mass
M is molar mass of gas
R = 0.08
0.986 × 0.25 = (0.44/M) × 0.08 × 300
M = 0.44 × 0.08 × 300 / 0.986 × 0.25
M = 10.56 / 0.24 = 44 gram/mol
Therefore, the molar mass of unknown gas is 44 gram/mol.
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in a capillary, pc is 30 mm hg, pi is -2 mm hg, πc is 25 mm hg, and πi is 2 mm hg. if filtration coefficient (kf) is 0.5 ml/min/mmhg, what is the rate of water flow across the capillary wall
Net filtration would be reduced if the osmotic pressure in the glomerular capillaries rose from 28 mm hg to 35 mm hg.
What is osmotic pressure?
Pressure in the glomerular capillary 69 mmHg
Pressure in the capsular space 15mm Hg
The colloid osmotic pressure 30 mm Hg
Also no plasma proteins are filtered by the glomerulus
In this scenario -
Net filtration pressure is equal to
Pressure in the glomerular capillary Pressure in the capsular space colloid osmotic pressure
Substituting the given values in above equation, we get -
69-30-15
24 mm Hg
The osmotic pressure is the least amount of pressure that must be applied to a solution in order to block the passage of the solution's pure solvent through a semipermeable membrane. It can alternatively be described as a measurement of a solution's propensity to osmotically absorb a pure solvent. The highest osmotic pressure that may form in a solution if it were cut off from its pure solvent by a semipermeable membrane is known as the potential osmotic pressure.
When two solutions with various solute concentrations are separated by a selectively permeable membrane, osmosis takes place.
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What is the empirical formula mass of c4h6f2? (atomic masses: c = 12 amu, h = 1 amu, f = 19 amu). enter your value as a whole number.
Molar Mass, Molecular Weight and Elemental Composition Calculator ; Carbon, C · 12.0107, 4, 52.1710 ; Hydrogen, H · 1.00794, 6, 6.5673.
What is Molar Mass,?The mass of a sample of a chemical compound is divided by the quantity of that substance, or the number of moles in the sample, measured in moles, to obtain the compound's molar mass in chemistry.
In contrast to molecular properties, a substance's molar mass is a bulk property. The compound is present in many different forms, each with a different mass as a result of the isotopes. The molar mass is the average of these masses. The molar mass is most frequently calculated using the standard atomic weights and is a function of the relative abundance of the constituent atoms' isotopes on Earth. It is thus a terrestrial average. In order to convert between a substance's mass and its amount, the molar mass is the suitable unit.
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What is the arrangement of the particles in stearic acid when it is a solid and when it is a liquid?
Answer:
With an 18-carbon backbone, stearic acid is a saturated long-chain fatty acid.
What is Stearic Acid?
With an 18-carbon chain, stearic acid is a saturated fatty acid. Octadecanoic acid is the substance's IUPAC name. It has the chemical formula C₁₇H₃₅CO₂H and is a waxy solid. The word "stear," which means tallow in Greek, is where it gets its name. Stearates are the names for the salts and esters of stearic acid. The second most prevalent saturated fatty acid in nature after palmitic acid is stearic acid, which serves as its ester. [11] Stearin is the triglyceride produced when three molecules of stearic acid are combined.
Explanation:
Animal fat contains more stearic acid than vegetable fat does. The foods cocoa butter and shea butter are the notable exceptions because they contain stearic acid (as a triglyceride).
In terms of its biosynthesis, acetyl-CoA contributes two-carbon building blocks to the fatty acid synthesis machinery, which converts carbohydrates into stearic acid.
The triglycerides in fats and oils are saponified with hot water to produce stearic acid. After that, the resulting mixture is distillated.
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A chemical engineer has determined by measurements that there are 42. moles of hydrogen in a sample of methyl tert-butyl ether. how many moles of oxygen are in the sample?
In a methyl tert-butyl ether sample that contains 69.0 moles of hydrogen, there are 5.75 moles of oxygen.
What is methyl tert-butyl ether?Methyl tertiary-butyl ether (MTBE), also known as methyl tert-butyl ether and tert-butyl methyl ether, is an organic chemical with the structural formula (CH3)3COCH3. MTBE is a colorless, flammable liquid that is only weakly soluble in water. MTBE is primarily a fuel additive that is mixed with gasoline to improve knock resistance and cut back on unwelcome emissions.
Methanol and isobutylene combine chemically to produce MTBE. Natural gas, especially methane, contains a variety of light hydrocarbons that steam reforming can transform into carbon monoxide and hydrogen. The resultant gases then continue to react in the presence of a catalyst to produce methanol. There are numerous ways to make isobutylene.
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9. a dosage is prescribed as 8.70 mg of medicine per kg of body weight. how many mg of medicine should be given to a 182 pound person? round your answer to a whole number (the ones place).
The amount of medicine that should be given to a 182-pound person is 718 mg.
To calculate the dosage of medicine we have to first convert the weight of a person from pound to kg
We know that,
1 pound = 0.454 kg
Thus, the weight of a person weighing 182 pounds is 182 x 0.454 = 82.628 kg.
The dosage prescribed is 8.70 mg of medicine per kg of body weight.
Thus, the dosage for 82.62 kg comes out to be 82.62 x 8.70 = 718.78 mg.
Thus, the amount of medicine that should be given to a 182-pound person is 718 mg.
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Carbon-14 has a half-life of 5730 yrs. what activity (in dps) would be expected for a 25.3 mg sample of carbon-14?
Activity would be expected for a 25.3 mg sample of carbon-14 is 25.296
Here given data is Carbon-14 has a half-life of 5730 yrs and expected for a 25.3 mg sample of carbon-14 =?
So here half life of Carbon-14 is t1/2=5730 yrs
This means that 5730 yrs the initial amount of carbon-14 will be halved
The radioactive constant is λ=ln2/t1/2 = ln2/5730=0.000121
The fundamental decay equation is m=m0e⁻λt
Initial amount of carbon-14 is m0=25.3
Therefore, 25.3×e⁰⁰⁰⁰¹²¹=25.296
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the radioactive element carbon-14 has a half-life of 5750 years. a scientist determined that the bones from a mastodon had lost % of their carbon-14. how old were the bones at the time they were discovered?
The bones are approximately 7539 years old.
Exponential Decay :A radioactive substance follows the model of exponential decay. This is the model that predicts the half-life of substances. It is given by the following exponential equation.
[tex]A = A_{0}e^{-kt}[/tex]
Where
[tex]A_{0}[/tex] is the initial amount present at the start,
t is the time, and
k is the constant that governs the rate of decay. Use this model to solve the age of the bones.
Evaluating the question :
When a radioactive substance reaches its half-life, half its original amount will be decayed away due to radiation. Using the exponential decay model,
[tex]A = A_{0} e^{-kt}[/tex]
substitute [tex]A = \frac{1}{2} A_{0}[/tex], and the half-life of the element to determine k completing the full model of the decay.
[tex]\frac{1}{2}A_{0} = A_{0} e^{- 5750k}[/tex]
The first thing to do, is to divide both sides with [tex]A_{0}[/tex]
[tex]\frac{\frac{1}{2}A_{0} }{A_{0} } = \frac{A_{0}e^{-kt} }{A_{0} } \\ \frac{1}{2} = e^{-5750k}[/tex]
Now, take the natural logarithm of both sides of the equation.
[tex]ln(\frac{1}{2}) = ln e^{-5750k}[/tex]
[tex]ln(\frac{1}{2}) = -5750k[/tex]
Divide both sides of the equation with −5750, then evaluate using a logarithm table or a calculator.
[tex]k = 1.2054734[/tex]× [tex]10^{-4}[/tex]
Now, that the constant is determined, this means the exponential decay of the radioactive substance is modeled by the following equation.
[tex]A = A_{0} e^{- 1.2054734 * 10^{-4} }[/tex]
The bones that were found lost 59.7% of the carbon-14 originally present. Using symbols, this can be written as,
[tex]A = A_{0} - 59.7%\\\\A = A_{0} ( 1 - 0.597)\\\\A = 0.403A_{0}[/tex]
This means that only 40.3 % of the radioactive substance remained. Substitute this to the mathematical model above, then solve for the time in years.
[tex]0.403A_{0} = A_{0} e^{-1.2054734 *10^{-4} }[/tex]
Now, take the natural logarithm of both sides of the equation.
[tex]ln0.403 = -1.2054734 *10^{-4} t[/tex]
Now, solve for t by dividing both sides of the equation with −1.2054734 ×
[tex]10 ^{-4}[/tex]
Evaluate using a logarithm table or a calculator.t = 7539.10 years
Therefore, the bones are approximately 7539 years old.
Half life of radioactive element :The half-life of a radioactive isotope is that the amount of time it takes for one-half of the radioactive isotope to decay. The half-life of a selected radioactive isotope is constant; it is unaffected by conditions and is independent of the initial amount of that isotope
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you find that a material with a mass of 45 grams occupies a space of 1 cubic centimeter; what measurement with derived units could you determine?
The material with a mass of 45 grams occupies a space of 1 cubic centimeter, the measurement given is density.
What is density?
Any unit that is defined as mass divided by volume is a mass density according to the density equation ( = m/V). There are numerous units for mass density in use due to the great number of units of mass and volume used to represent a wide range of magnitudes.
The two units for density that are perhaps most frequently used are the SI unit of kilogram per cubic metre (kg/m3) and the cgs unit of gram per cubic centimeter (g/cm3). There are 1000 kg/m3 in one g/cm3.
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For a second order reaction where concentration is measured in molarity and time is measured in seconds, the units on the rate constant must be:___.
For a second order reaction where concentration is measured in molarity and time is measured in seconds.
The unit for the rate constant of a second order reaction is Lmol −1s −1 .
What is molarity?
For a second order reaction, rate=k[A] 2
molL −1s −1 =k(molL −1) 2
k=Lmol −1s −1
The molarity of a solution is the quantity of solute in moles per litre of solution. Molarity is represented by a capital M. A solution is a combination of two or more compounds in chemistry in which neither substance undergoes chemical change. For instance, salt water is a mixture of salt and water (the solvent) (the solute).
Therefore,
For a second order reaction where concentration is measured in molarity and time is measured in seconds, the units on the rate constant must be
The unit for the rate constant of a second order reaction is Lmol −1s −1 .
For a second order reaction, rate=k[A] 2
molL −1s −1 =k(molL −1) 2
k=Lmol −1s −1
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How does a certain frequency of line occur in the hydrogen spectrum?
Answer: Your welcome!
Explanation:
A certain frequency of line in the hydrogen spectrum occurs when an electron in the atom transitions from one energy level to another, releasing or absorbing a photon of light with a specific frequency. This frequency is determined by the energy difference between the two levels and is referred to as the Rydberg equation. The Rydberg equation specifies the frequency of the photon as a function of the energy levels and the mass of the electron. The frequency of a line in the hydrogen spectrum is therefore determined by the energy difference between the two levels, as well as the mass of the electron.