Answer:
beta to Kr-80 or Se-80
Explanation:
sorry if wrong
How much heat must be added to a 8.21 g sample of gold to increase its temperature from the tempe
75.3°C to 83.1°C? The specific heat of gold is 0.13 J/gºC
Answer:
Q= ms∆T
Where, m is mass of substance
S is specific heat
∆T is temperature change
As in question , m=8.21 ,s=0.13 ,∆T =6.2
So, Q = 8.21×0.13×6.2=6.61 J
Please help help helpppppppp
Darren looks up at night and sees a bright object with a tail moving quickly across the sky. What is the most likely object that Darren saw? A. an asteroid B. a meteor C. a comet . D. a cupid
Answer:
A
Explanation:
asteroids most often leave trails due to the large amount of friction that occurs.
The bright spatial object with a tail moving fastly across the sky is called a comet. Comets are made of rock, dust and ices.
What are comets?Comets are orbiting snowballs around sun made of frozen gases, rock, and dust. They enlarge to the size of a sizable town when frozen. A comet heats up and ejects dust and gases into a huge, blazing head that is larger than most planets when its orbit puts it near to the Sun.
Millions of kilometers away from the sun, the dust and gas combine to form a tail. The Kuiper Belt and much further Oort cloud are presumably home to billions of comets that orbit our sun.
Some of their ice begins to melt and boil off as the comet approaches the sun, along with some dust. The coma, which is created by these particles and gases, surrounds the nucleus.
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How many theoretical plates produce a chromatography peak eluting at 12.83 min with a width at half-height of 8.7 s
Serena mixed two samples together: a gray solid that smells like flowers and a gray solid that smells like bleach. She analyzed the results and found two ending substances. One of the ending substances was a white solid. This ending substance is made up of the repeating group of atoms shown above. Which of the diagrams to the left shows the repeating groups of atoms that make up the samples Serena mixed together?
The diagrams that shows the repeating groups of atoms that make up the samples which were mixed together is option D.
A chemical reaction is said to have occurred when there a rearrangement of atoms in a substance. This rearrangement of atoms in the substance leads to the formation of new substances.
In this case, we must note that the combination of reactants to be chosen must posses the atoms shown as part of the one of the end substance. The only option that satisfies this requirement is option D.
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Answer:D
Explanation:DDDDD
Which of the following could be classified as unleavened bread?
sourdough bread
muffins
tortilla
bagels
Answer:
Tortilla
Explanation:
Answer:
tortilla
Explanation:
What is the balanced form of the chemical equation shown below?
N2(g) + H2(9) ► NH3(9)
O A. N2(9) + H2(9) ► NH3(9)
B. N2(9) + H2(g) → 2NH3(9)
)
O C. N2(g) + 3H2(g) → 2NH3(9)
O 9
D. N2(9) + H2(g) → 2NH(9)
Answer:
C
Explanation:
2 N on left so we put a 2 on the right which makes 6 H so we need 6H on the left to do that we add a coef. of 3 to make 6 H and balance the equation
Calculate the number of mole of NaOH needed to prepare 250 mL 0.30 M NaOH solution. (Relative Atomic Mass: Na = 23.0; H = 1.0; O = 16.0]
A)75.00 mol
B)0.833 mol
C)1.200 mol
D) 0.075 mol
Answer:
The answer is letter D. 0./75 mol
Explanation:
Explanation: It's a 3.0 M solution so 1 litre of solution contains 3 moles of NaOH. 250 ml of solution therefore contains 0.25 x 3 = 0.75 moles of NaOH.
I figured it out no problem
Answer:
good job ;0
Explanation:
What element makes up graphene
Nitric oxide (NO) from car exhaust is a primary air pollutant. Calculate the equilibrium constant for the reaction
N2(g) + O2(g) equilibrium reaction arrow 2 NO(g)
at 25°C using the data listed in the supporting materials.
Calculate the equilibrium constant at 1496°C, which is a typical temperature inside the cylinders of a car's engine after it has been running for some time. (Assume that both ΔrH° and ΔrS° are temperature independent.)
This problem is asking for the equilibrium constant at two different temperatures by describing the chemical equilibrium between gaseous nitrogen, oxygen and nitrogen monoxide at 25 °C and 1496 °C as the room temperature and the typical temperature inside the cylinders of a car's engine respectively:
N₂(g) + O₂(g) ⇄ 2 NO(g)
Thus, the calculated equilibrium constants turned out to be 6.19x10⁻³¹ and 9.87x10⁻⁵ at the aforementioned temperatures, respectively, according to the following work:
There is a relationship between the Gibbs free energy, enthalpy and entropy of the reaction, which leads to the equilibrium constant as shown below:
[tex]\Delta _rG=\Delta _rH-T\Delta _rS\\\\\Delta _rG=-RT ln(K)[/tex]
Which means we can calculate the enthalpy and entropy of reaction and subsequently the Gibbs free energy and equilibrium constant. In such a way, we calculate these two as follows, according to the enthalpies of formation and standard entropies of N₂(g), O₂(g) and NO(g) since these are assumed constant along the temperature range:
[tex]\Delta _rH=2*90.25 kJ/mol - (0 kJ/mol+0 kJ/mol)=180.5kJ/mol\\\\\Delta _rS=2*(0.211 kJ/mol*K)-(0.192kJ/mol*K+0.205kJ/mol*K)=0.025kJ/mol*K[/tex]
Then, we calculate the Gibbs free energy of reaction at both 25 °C and 1496 °C:
[tex]\Delta _rG_{25\°C}=180.5-(25+298.15)*0.025=172.42kJ/mol\\\\\Delta _rG_{1496\°C}=180.5-(1496+298.15)*0.025=135.65kJ/mol[/tex]
And finally, the equilibrium constants derived from the general Gibbs equation and Gibbs free energies of reaction:
[tex]K=exp(-\frac{\Delta _rG}{RT} )\\\\K_{25\°C}=exp[-\frac{172420 J/mol}{(8.3145\frac{J}{mol*K})(298.15K)} ]=6.19x10^{-31}\\\\K_{1496\°C}=exp[-\frac{135650J/mol}{(8.3145\frac{J}{mol*K})(1769K)} ]=9.87x10^{-5}[/tex]
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(Gibbs free energy) https://brainly.com/question/15213613It takes about 38 m3 of boards and plywood to build an average-size, single-family home. Can an average-size, single-family home be built with one day’s output from the saw mill? About how many days will it take for the saw mill to produce enough lumber to build a neighborhood of 100 average-size homes?
A) The answer to whether an average-size, single-family home be built with one day’s output from the saw mill is; No, it can't be built from one days output
B) The number of days will it take for the saw mill to produce enough lumber to build a neighborhood of 100 average-size homes is; 1100 days
A) From research, the average size capacity saw mill usually produces around 1500 board feet of boards per day.
Now, converting board ft to cubic meter gives;
1 board feet = 1/424 m³
Thus; 1500 board feet = 1500 * 1/424 ≈ 3.54 m³
Now, we are told that it takes 38 m³ of boards and plywood to build an average size single family home.
Since one days output = 3.54 m³
It is less than the volume required for the average sized house and so the daily output will not be sufficient.
B) Number of days to produce enough boards and plywood for the average sized family home = 38/3.54 ≈ 11 days
Thus, for 100 homes;
Number of days = 100 * 11 = 1100 days
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Potassium hydrogen phthalate, KHP, is a monoprotic acid often used to standardize NaOH solutions. If 0.212 g of KHP are dissolved into 50.00 mL of water and titrated with 35.00 mL of NaOH, what is the molarity of NaOH. Molar mass of KHP
The molarity of the NaOH solution is 0.03 M
We'll begin by calculating the mole of the KHP
Mass = 0.212 g Molar mass = 204.22 g/mol Mole of KHP =?Mole = mass /molar mass
Mole of KHP = 0.212 / 204.22
Mole of KHP = 0.001 mole
Next, we shall determine the molarity of the KHP solution
Mole of KHP = 0.001 mole Volume = 50 mL = 50/1000 = 0.05 L Molarity of KHP =?Molarity = mole / Volume
Molarity of KHP = 0.001 / 0.05
Molarity of KHP = 0.02 M
Finally , we shall determine the molarity of the NaOH solution
KHP + NaOH —> NaPK + H₂O
From the balanced equation above,
The mole ratio of the acid, KHP (nA) = 1The mole ratio of base, NaOH (nB) = 1From the question given above, the following data were obtained:
Volume of acid, KHP (Va) = 50 mL Molarity of acid, KHP (Ma) = 0.02 M.Volume of base, NaOH (Vb) = 35 mL Molarity of base, NaOH (Mb) =?MaVa / MbVb = nA / nB
(0.02 × 50) / (Mb × 35) = 1
1 / (Mb × 35) = 1
Cross multiply
Mb × 35 = 1
Divide both side by 35
Mb = 1 / 35
Mb = 0.03 M
Thus, the molarity of the NaOH solution is 0.03 M
Complete question:
See attached photo
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How many electrons does chlorine need to gain in order to be like Argon ?
- 2 electrons
- 3 electrons
- 1 electron
WHICH ONE?????????????????? Brainlest
Answer:
I believe it would be C, The number of atoms in the reactants is equal to the number of atoms composing the products
Explanation:
hope this helps! :D
have a miraculous day!! <3
Answer:
The number of atoms in the reactants is equal to the number of atoms composing the products
Describe four characteristics of S-block elements
1. s block elements have spherical s orbital as
their outermost orbital.
2. Since s orbital can accommodate a maximum of 2 electrons, each one of these elements have 1 or two electrons.
3. These s electrons are lost very easily to form
monopositive ions by Isoing one electron in the
outermost orbital or dipositive ions by losing 2
electrons.
4. They have low ionisation potentials and low electronegativities.
5. They are good conductors of heat and electricity, excepting H2 and He.
6. They are silvery, shiny metallic substances, (with the exception of hydrogen and helium which gaseous nonmetals).
7. They are malleable and ductile, i.e., we can
make sheets and wires from them, (exception:
H2, He)
8. They readily form ionic salts with most nonmetals.
hope it helps plzzz mark as brainliest
3 moles of nitrogen and 5 moles of hydrogen react to form ammonia. Use the balanced equation below to determine which is the limiting reactant.
N2 + 3H2 --> 2NH3
Answer:
H₂ is the limiting reactant
Explanation:
Balanced equations demonstrate the ratios of all reactants and products in terms of the number of atoms/molecules or moles;
In the given reaction:
1 mol of N₂ reacts with 3 mol of H₂ to produce 2 mol of NH₃
So the ratio of N₂ to H₂ to NH₃ will be 1:3:2
If we have 3 moles of N₂, we can apply the ratio to find that it will react with 9 moles of H₂ (3× the moles of N₂) to produce 6 moles of NH₃ (2× the moles of N₂);
Similarly, if we have 5 moles of H₂, then applying the ratio, we find that ⁵/₃ or 1.66... moles of N₂ (¹/₃× the moles of H₂) react with 5 moles of H₂ to produce ¹⁰/₃ or 3.33... moles of NH₃ (²/₃× the moles of H₂);
In order for all of the 3 moles of N₂ to react, it would require 6 moles of H₂;
There is only 5 moles of H₂ available, meaning there will be an excess of N₂;
5 moles of H₂ will react with 1.66... moles of the N₂, leaving 1.33... or ⁴/₃ moles of N₂ unreacted;
If the N₂ is in excess, then the H₂ is limited (i.e. the limiting reactant)
CO 2 is an element. true or false
Answer: false
Explanation:
f this helps typically an element wont have a 2 next to it, to see if something is an element or compound check for the element on the periodic table and see if the structure or name matches the one given to you on the question. for example here it is Co2 on the periodic table it's simply written as Co
co2 or carbon dioxide is a compound not an element, you can even check this on the periodic table
Answer:
true
Explanation:
co2 is carbon dioxide
Hope this helps.
help plzzzzzzzzzzzzzzzzz
Answer:
C
I hope that this helps.
Which event is an example of an exothermic reaction?(1 point)
A. Combustion
B. Evaporation
C. Decomposition
D.Melting ice
Answer:
Combustion
Explanation:
An exothermic reaction is defined as a reaction that releases heat and has a net negative standard enthalpy change. Examples include any combustion process, rusting of iron, and freezing of water.
Combustion is a type of exothermic chemical reaction that generates light and heat in most cases, and occurs fairly quickly.
What is an exothermic reaction?An exothermic reaction is one that when it occurs releases energy in the form of heat or light to the environment.
Characteristics of an exothermic reactionWhen this type of reaction occurs, the products obtained have lower energy than the initial reactants.Most of the exothermic reactions are oxidation, and when they are very violent they can generate fire, as in combustion.Combustion is a very fast oxidation reaction that occurs between materials called fuels and oxygen.Therefore, we can conclude that combustion is an example of an exothermic reaction that releases large amounts of heat, which can lead to fire.
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pa help po science po
Answer:
1. molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem, biosphere
2. A
3. D
4. C
5. C
6. C
7. C
8. B
9. Sorry I don't know :(
10. B
11. A
12. C
13. Sorry :((
14. C
15. a
16. d
Sorry I don't know the rest.. I hope this helps though!!
what are nanofluids and how they work?
Answer:
What is nanofluids?
Nanofluids are engineered suspensions of nanometer-sized solid particles in a base fluid. Suspending small solid particles in the energy transmission fluids can improve their thermal conductivity and provides an effective and innovative way to enhance their heat transfer characteristics significantly.
How nanofluids work?
Nanofluid refers to the dispersion of metal or non-metal nano-powder into traditional heat exchange media such as water, alcohol, and oil to prepare a uniform, stable and high thermal conductivity. The traditional heat exchange medium has a low thermal conductivity and has been unable to meet the growing demand for industrial engineering heat exchange. The thermal conductivity of some metal or non-metal nanoparticles is often hundreds of times higher than that of heat-conducting media. For example, common silicon carbide nanoparticles have a thermal conductivity of 170-270 W/m•K. The researchers found that if the nanoparticles can be uniformly and stably dispersed in the heat transfer medium, the thermal conductivity of the nanoparticles will be greatly improved.
name the main form of energy released by the reaction between hydrogen and oxygen inside a combustion engine
Answer:
When molecular hydrogen (H2) and oxygen (O2) are combined and allowed to react together, energy is released and the molecules of hydrogen and oxygen can combine to form either water or hydrogen peroxide . These two processes are represented by the two chemical equations shown at right.
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graph
1. You represented the allele for green peas with green clay and the allele for yellow peas with yellow clay. Are the alleles really these colors?
Answer:
pure-bred green with pure-bred yellow peas. Since yellow is dominant to green, all of the offspring were yellow. The green phenotype had disappeared. ... When a pure-bred green plant is crossed with a pure-bred yellow plant, the offspring inherit one allele of the color gene from each parent.
Explanation:
Ppbag at it again
Michelle is trying to find the average atomic mass of a sample of an unknown
element. She finds that her sample contains 59.34% of an isotope with a mass of
113.6459, while the rest of the sample is an isotope with a mass of 115.8488. What
is the average atomic mass of her sample? Please round your answer to 0.01 amu.
The average atomic mass of her sample is 114.54 amu
Let the 1st isotope be A
Let the 2nd isotope be B
From the question given above, the following data were obtained:
Abundance of isotope A (A%) = 59.34% Mass of isotope A = 113.6459 amuMass of isotope B = 115.8488 amuAbundance of isotope B (B%) = 100 – 59.34 = 40.66%Average atomic mass =?The average atomic mass of the sample can be obtained as follow:
[tex]Average \: atomic \: mass \: = \frac{mass \: of \: A \times A\%}{100} + \frac{mass \: of \: B \times B\%}{100} \\ \\ Average \: atomic \: mass \: = \frac{113.6459\times 59.34}{100} + \frac{115.8488\times 40.66}{100} \\ \\ Average \: atomic \: mass \: = 114.54 \: amu \\ \\ [/tex]
Thus, the average atomic mass of the sample is 114.54 amu
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If there is .03L of NaOH in a flask, how can a .12M solution of H2SO4 be used to determine the concentration of NaOH in the reaction?
The concentration of NaOH in the reaction can be determined using the Titration method.
The concentration of NaOH in the reaction can be determined by titration.
A burette if filled with the known concentration of H₂SO₄ and then titrated against the known volume of NaOH in a conical flask. An indicator is used in order to determine the end-point of the titration process. At the end-point of the titration, the volume of acid used is recorded.
Next, we will write the balanced chemical equation of the reaction.
The balanced chemical equation for the reaction is
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O
This means 2 moles of NaOH is required to neutralize 1 mole of H₂SO₄
Now, we can determine the concentration of NaOH by using the titration formula.
[tex]\frac{C_{A}V_{A} }{C_{B}V_{B}} = \frac{n_{A}}{n_{B}}[/tex]
Where [tex]C_{A}[/tex] is the concentration of acid
[tex]V_{A}[/tex] is the volume of acid
[tex]C_{B}[/tex] is the concentration of base
[tex]V_{B}[/tex] is the volume of base
[tex]n_{A}[/tex] is the mole ratio of acid
[tex]n_{B}[/tex] is the mole ratio of base
Then, we put the respective parameters, including the volume of acid determined from the titration process, into the formula to determine the concentration of the NaOH.
Hence, the concentration of NaOH in the reaction can be determined using the Titration method.
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Calculate the wavelength of X-rays of frequency 5.00 x 100 Hz (Hz=Hertz=cycles/sec).
a) 1.20 nm
b) 0.398 nm
C) 0.600 m
d) 1.20 m
e) 0.600 nm
Answer:
no correct answer please mention other answers.
wavelength=30000000/frequency
Read the statement. Magnesium atoms have 12 electrons, with the configuration 2-8-2. If the first five ionization energies of magnesium are shown, which ionization energy would show a sudden sharp increase?
The electronic configuration of magnesium is:
1s² 2s² 2p⁶ 3s² = [Ne] 3s²
This means that for a magnesium atom, in order to have its outermost orbital full, the easiest way would be to lose the two outermost electrons. This is seen in its relatively low first two ionization energies. The third ionization energy is several times higher because the ion would move from a stable form to an highly unstable form. (Mg⁺² → Mg⁺³ + e⁻).
Sodium only has one electron in its outermost orbital, so its first ionization energy would be several times lower than the second.
why do we need to study thermodynamics?
A sample of N2O gas has a density of 2.95 g/L at 298 K. What must be the pressure of the gas?
[tex]\huge{\underline{\underline{\boxed{\sf{\purple{ǫᴜᴇsᴛɪᴏɴ}}}}}}[/tex]
A sample of N2O gas has a density of 2.95 g/L at 298 K. What must be the pressure of the gas?[tex]\huge\fcolorbox{aqua}{lime}{Answer}[/tex]
P = 1203 mm Hg[tex]\huge{\underline{\underline{\boxed{\sf{\purple{Explanation}}}}}}[/tex]
#Given: -p = 2.85 g/LT = 298 K# Solution :-According to ideal gas equation -
➡PV = nRT
➡PV = (W/M)RT
➡PM = (W/V)RT
➡PM = PRT
➡P = pRT/M
➡P = 2.85 × 0.082 x 298 / 44
➡P = 1.583 atm
➡P = 1.583 × 760
➡P = 1203 mm Hg
Therefore, pressure of the gas. must be1203 mm of Hg.Hope this helps you:)