Answer:
b, c, e
Explanation:
Inorganic compounds usually lack carbon.
Inorganic compounds are not associated with or made from living things.
Inorganic compounds include salt and water.
Answer:
yes the answer id bce
Explanation:
10. When the pressure on a gas inetcases three times, by how much will the volume incrcase or decrease?
Answer:The answer to this question comes from experiments done by the scientist Robert Boyle in an effort to improve air pumps. In the 1600's, Boyle measured the volumes of gases at different pressures. Boyle found that when the pressure of gas at a constant temperature is increased, the volume of the gas decreases. when the pressure of gas is decreased, the volume increases. this relationship between pressure and volume is called Boyle's law.
Explanation: So, at constant temperature, the answer to your answer is: the volume decreases in the same ratio as the ratio of pressure increases.
BUT, in general, there is not a single answer to your question. It depend by the context.
For example, if you put the gas in a rigid steel tank (volume is constant), you can heat the gas, so provoking a pressure increase. But you won't get any change in volume.
Or, if you heat the gas in a partially elastic vessel (as a tire or a soccer ball) you will get both an increase of volume AND an increase of pressure.
FINALLY if you inflate a bubblegum ball, the volume will be increased without any change in pressure and temperature, because you have increased the NUMBER of molecules in the balloon.
There are many other ways to change volume and pressure of a gas that are different from the Boyle experiment.
the perimeter of a isosceles is 48 meters. the upper base is 12 meters shorter than the lower base x.each leg is 12 meters shorter than the lower base x. each leg is 12 meters shorter than the lower base. write the equation of the perimeter in terms of x.
using the following balanced chemical equation: PCL5 -> PCL3 + CL2 and knowing that Keq = 7.9, [PCL3] = 0.054M and [CL2] = 0.34M
a. write the Keq expression for the reaction
b. find the [PCL5]
c circle the correct answer: the reaction favored is the (forward, reverse)
Answer:
see explanations
Explanation:
PCl₅ => PCl₃ + Cl₂
C(eq): [PCl₅] 0.054M 0.34M
a. Keq = [PCl₃][Cl₂]/[PCl₅]
b. 7.9 = (0.054)(0.34)/[PCl₅] => [PCl₅] = (0.054)(0.34)/(7.9) = 0.0023M
c. If [PCl₃] = 0.054M; [Cl₂] = 0.34M and [PCl₅] = 0.0023M then the reaction is at equilibrium and will not shift forward or in reverse. In order to determine if reaction is not at equilibrium, a set of concentration values needs to be given in problem, used to calculate Qeq and compared to the given Keq value. The following defines direction of shift ...
Keq < Qeq => rxn shifts left
Keq = Qeq => rxn is at equilibrium (no shift)
Keq > Qeq => rxn shifts right
NOTE: If Keq is listed first followed by Qeq in the above conditions, the inequality symbol indicates direction of shift.
Metamorphic rocks directly form from
Answer:
Metamorphic rocks are formed from pre-existing rock and sediment materials. They are formed when igneous, sedimentary, or other pre-existing metamorphic rocks are exposed to the heat and pressure as well as super-heated mineral-rich fluids. They are compacted together to form a new rock altogether. Metamorphism does not include the melting or liquefaction of the pre-existing rock. Instead, it compacts them and crushes them, pushing them together at extreme heat and pressure to form a new rock altogether composed of sedimentary, igneous, and other metamorphic rock. It's the rock hybrid of the geologic world.
Metamorphism is similar to when you squish playdough together, it doesn't form a new playdough color (unless you REALLY mixed that poor playdough together). It forms an amalgamation of different colors and patterns made from the other rock.
Taken from a paper I once wrote I explained this again:
"Metamorphic rocks are formed when pre-existing rocks and their minerals are compressed and altered by Earth’s internal processes; interior pressure, temperature (heat), and chemical reactions. The minerals and pre-existing rock necessary for the creation of metamorphic rock must then also be located deep underground if such processes are expected to make an impact and create a metamorphic rock."
6.) (5 points) Assume you have a system with a fixed pH of 4.0. It is well buffered and therefore the pH will not change. What is the predominant state of a molecule with a dissociable proton with a pKa of 5.2 if it is introduced to that system (protonated or deprotonated)
Answer:
Dissociated state is the predominant one
Explanation:
When a molecule with pKa of 4.52 is in an aqueous solution at pH = 4.0, follows the H-H equation, thus:
pH = pKa + log₁₀ [A⁻] / [HA]
Where [A⁻] is the dissociated state and [HA] represents the protonated state
Replacing:
4.0 = 5.2 + log₁₀ [A⁻] / [HA]
-1.2 = log₁₀ [A⁻] / [HA]
0.063 = [A⁻] / [HA]
[HA] = 16 [A⁻]
That means you have 16 times more [HA] than [A⁻] and the dissociated state is the predominant one
Dysphagia is the name of a disorder that disrupts
А
the swallowing reflex
B
the absorption of essential nutrients
acid levels in the stomach
C
D
the stomach lining
Answer:
A. The Swallowing reflex
Explanation:
Dysphagia Is a a condition that makes swallowing difficult.
Which diagram correctly describes the changes that occur as a small piece of rock falls from space and hits the earth
Answer:
the motion of gravity
Explanation:
Answer:
its c
Explanation
advhuosijoklxcmnjdabsuhggggabciaciudeifweingivg eygerigsygfe97rsghisdcvhbsduigwiugfu9uigdgiurfgyisdgfsdgfegiygewifgsdygfewusgfuyesigf7wgfiesgfiusgdfies
the diagram above represents a reflex arc in a human. This pathway responds when someone touches something that causes pain, such as a hot stove. Which of the following shows the correct order of the body systems involved in this response?
A) Integumentary, respiratory, digestive
B) Circulatory, respiratory, nervous
C) Integumentary, nervous, muscular
D) Circulatory, digestive, nervous
Answer:
C) Integumentary, nervous, muscular
Explanation:
When a human body touches a hot stove , our sense organ which is integumen first of all receives the impulse of heat . The impulse is transformed into electrical signal which is transmitted to brain which is a part of nervous system . Then brain processes it and command signal is sent to muscle of hand to move it away from that place . Hence the order is
Integumentary, nervous, muscular .
If you collect 1.75 L of hydrogen gas during a lab experiment, when the room temperature is 23ºC and the barometric pressure is 105 kPa, how many moles of hydrogen will you have?
Answer:
[tex]n=0.0747mol[/tex]
Explanation:
Hello,
In this case, since we can consider hydrogen gas as an ideal gas, we check the volume-pressure-temperature-mole relationship by using the ideal gas equation:
[tex]PV=nRT[/tex]
Whereas we are asked to compute the moles given the temperature in Kelvins, thr pressure in atm and volume in L as shown below:
[tex]n=\frac{105kPa*\frac{0.009869atm}{1kPa}*1.75L}{0.082\frac{atm*L}{mol*K}*(23+273.15)K} \\\\n=0.0747mol[/tex]
Best regards.
A molecule of which compound has a multiple covalent bond?
1. CH4
2. C2H4
3. C3H8
4. C4H10
Answer:
The second one
Explanation:
Because not only did I take a castle learning in this today but c2h4 has 6 covalent bonds
There are several types of molecules that have multiple bond. A molecule of which compound has a multiple covalent bond is C2H4.
Covalent bonding is the sharing of one or more electron pairs. In many covalent bonding situations,
Multiple chemical bonds exist when there is more than one electron pair that is being shared.
A nitrogen atom often fill its octet by sharing three electrons with another nitrogen atom thereby creating three covalent bonds.
Multiple bonds are commonly found in organic compound and they have carbon molecules.
Learn more from
https://brainly.com/question/4985972
A 99.8 mL sample of a solution that is 12.0% KI by mass (d: 1.093 g/mL) is added to 96.7 mL of another solution that is 14.0% Pb(NO3)2 by mass (d: 1.134 g/mL). How many grams of PbI2 should form?
Pb(NO3)2(aq) + 2 KI(aq) PbI2(s) + 2 KNO3(aq)
Answer:
[tex]m_{PbI_2}=18.2gPbI_2[/tex]
Explanation:
Hello,
In this case, we write the reaction again:
[tex]Pb(NO_3)_2(aq) + 2 KI(aq)\rightarrow PbI_2(s) + 2 KNO_3(aq)[/tex]
In such a way, the first thing we do is to compute the reacting moles of lead (II) nitrate and potassium iodide, by using the concentration, volumes, densities and molar masses, 331.2 g/mol and 166.0 g/mol respectively:
[tex]n_{Pb(NO_3)_2}=\frac{0.14gPb(NO_3)_2}{1g\ sln}*\frac{1molPb(NO_3)_2}{331.2gPb(NO_3)_2} *\frac{1.134g\ sln}{1mL\ sln} *96.7mL\ sln\\\\n_{Pb(NO_3)_2}=0.04635molPb(NO_3)_2\\\\n_{KI}=\frac{0.12gKI}{1g\ sln}*\frac{1molKI}{166.0gKI} *\frac{1.093g\ sln}{1mL\ sln} *99.8mL\ sln\\\\n_{KI}=0.07885molKI[/tex]
Next, as lead (II) nitrate and potassium iodide are in a 1:2 molar ratio, 0.04635 mol of lead (II) nitrate will completely react with the following moles of potassium nitrate:
[tex]0.04635molPb(NO_3)_2*\frac{2molKI}{1molPb(NO_3)_2} =0.0927molKI[/tex]
But we only have 0.07885 moles, for that reason KI is the limiting reactant, so we compute the yielded grams of lead (II) iodide, whose molar mass is 461.01 g/mol, by using their 2:1 molar ratio:
[tex]m_{PbI_2}=0.07885molKI*\frac{1molPbI_2}{2molKI} *\frac{461.01gPbI_2}{1molPbI_2} \\\\m_{PbI_2}=18.2gPbI_2[/tex]
Best regards.
Answer:
Mass PbI2 = 18.19 grams
Explanation:
Step 1: Data given
Volume solution = 99.8 mL = 0.0998 L
mass % KI = 12.0 %
Density = 1.093 g/mL
Volume of the other solution = 96.7 mL = 0.967 L
mass % of Pb(NO3)2 = 14.0 %
Density = 1.134 g/mL
Step 2: The balanced equation
Pb(NO3)2(aq) + 2 KI(aq) ⇆ PbI2(s) + 2 KNO3(aq)
Step 3: Calculate mass
Mass = density * volume
Mass KI solution = 1.093 g/mL * 99.8 mL
Mass KI solution = 109.08 grams
Mass KI solution = 109.08 grams *0.12 = 13.09 grams
Mass of Pb(NO3)2 solution = 1.134 g/mL * 96.7 mL
Mass of Pb(NO3)2 solution = 109.66 grams
Mass of Pb(NO3)2 solution = 109.66 grams * 0.14 = 15.35 grams
Step 4: Calculate moles
Moles = mass / molar mass
Moles KI = 13.09 grams / 166.0 g/mol
Moles KI = 0.0789 moles
Moles Pb(NO3)2 = 15.35 grams / 331.2 g/mol
Moles Pb(NO3)2 = 0.0463 moles
Step 5: Calculate the limiting reactant
For 1 mol Pb(NO3)2 we need 2 moles KI to produce 1 mol PbI2 and 2 moles KNO3
Ki is the limiting reactant. It will completely be consumed ( 0.0789 moles). Pb(NO3)2 is in excess. There will react 0.0789/2 = 0.03945 moles. There will remain 0.0463 - 0.03945 = 0.00685 moles
Step 6: Calculate moles PbI2
For 1 mol Pb(NO3)2 we need 2 moles KI to produce 1 mol PbI2 and 2 moles KNO3
For 0.0789 moles KI we'll have 0.0789/2 = 0.03945 moles PbI2
Step 7: Calculate mass of PbI2
Mass PbI2 = moles PbI2 * molar mass PbI2
Mass PbI2 = 0.03945 moles * 461.01 g/mol
Mass PbI2 = 18.19 grams
Free radical mono-halogenation of an alkane is typically conducted using bromine versus chlorine because A.the bromine radical is more reactive and therefore more selective. B.the chlorine radical is more reactive and therefore more selective. C.the chlorine radical is less reactive and therefore more selective. D.the bromine radical is less reactive and therefore more selective. E.none of these choices.
Answer:Free radical mono-halogenation of an alkane is typically conducted using bromine versus chlorine because the bromine radical is less reactive and therefore more selective.
Explanation: Halogenation occurs when a halogen replaces one or more hydrogen atoms in an organic compound ie chlorine or bromine with the reactivity of the halogens decreasing in the order of F2 > Cl2 > Br2 > I2
Since fluorine reacts explosively making it is difficult to control, and iodine is unreactive. Free radical mono-halogenation of an alkane is typically conducted using bromine versus chlorine with Chlorination ie chlorine radical being more reactive and not selective and the Bromination of alkanes ie bromine radical occurring similarly but slower and less reactive but more selective which is due to the fact that a bromine atom is less reactive in the hydrogen abstraction than a chlorine atom evidence in the higher bond energy of H-Cl than H-Br.
For a school event 1/6 of the athletic field is reversed for the fifth -grade classes the reserved part of the field is divided equally Among the 4 fifth grade classes in the school what fraction of the whole athletic field is reserved for each fifth class
Answer:
[tex]\frac{1}{24}[/tex]
Explanation:
Given:
For a school event, 1/6 of the athletic field is reserved for the fifth -grade classes and the reserved part of the field is divided equally among the 4 fifth grade classes in the school.
To find: fraction of the whole athletic field reserved for each fifth class
Solution:
Fraction of the whole athletic field reserved for four fifth classes = [tex]\frac{1}{6}[/tex]
So, fraction of the whole athletic field reserved for each fifth class = [tex]\frac{1}{4}(\frac{1}{6})=\frac{1}{24}[/tex]
When Mrs. Green describes the physical properties of matter she said that physical properties often concern changes in state, One
physical property that does not describe a change in state is
A)
density
B)
evaporation
C)
freezing
D)
melting
Answer:
density
Explanation:
Density is an important measurement. It has an unit: g/mL or kg/L, ...
Evaporation, freezing, melting are the processes in which the substances change their states. Other processes are: condensation, sublimation, deposition.
...
Hope this answer can help you. Have a nice day!
Help me 6th grade science !:))
Answer:
I believe it is C.Shelter.
Answer:
C
Explanation:
The butterflies use the trees for shelter, because the trees protect them from the weather and the cold air.
Question 17 In the Haber reaction, patented by German chemist Fritz Haber in 1908, dinitrogen gas combines with dihydrogen gas to produce gaseous ammonia. This reaction is now the first step taken to make most of the world's fertilizer. Suppose a chemical engineer studying a new catalyst for the Haber reaction finds that 786. liters per second of dinitrogen are consumed when the reaction is run at 222.°C and 0.35atm. Calculate the rate at which ammonia is being produced. Give your answer in kilograms per second. Round your answer to 2 significant digits.
Answer:
Explanation:
N₂ + 3H₂ = 2 NH₃
1 vol 2 vol
786 liters 1572 liters
786 liters of dinitrogen will result in the production of 1572 liters of ammonia
volume of ammonia V₁ = 1572 liters
temperature T₁ = 222 + 273 = 495 K
pressure = .35 atm
We shall find this volume at NTP
volume V₂ = ?
pressure = 1 atm
temperature T₂ = 273
[tex]\frac{P_1V_1}{T_1} =\frac{P_2V_2}{T_2}[/tex]
[tex]\frac{.35\times 1572}{495} =\frac{1\times V_2}{ 273 }[/tex]
[tex]V_2 =303.44[/tex] liter .
mol weight of ammonia = 17
At NTP mass of 22.4 liter of ammonia will have mass of 17 gm
mass of 303.44 liter of ammonia will be equal to (303.44 x 17) / 22.4 gm
= 230.28 gm
=.23 kg / sec .
Rate of production of ammonia = .23 kg /s .
Glycolysis is the process by which energy is harvested from glucose by living things. Several of the reactions of glycolysis are thermodynamically unfavorable (nonspontaneous), but proceed when they are coupled with other reactions.
Reaction A: Pi+glucose⟶glucose-6-phosphate+H2OΔG=13.8 kJ/mol
Reaction B: Pi+fructose-6-phosphate⟶fructose-1,6-bisphosphate+H2OΔG=16.3 kJ/mol
Reaction C: ATP+H2O⟶ADP+PiΔG=−30.5 kJ/mol
Select every unfavorable reaction.
reaction B
reaction C
reaction A
Select every set of coupled reactions where the overall reaction is favorable.
reactions B and C
reactions A and B
reactions A and C
What is the net change in free energy if one set of reactions from the previous question is coupled so that the overall reaction is favorable? Note that if you selected more than one set of coupled reactions as favorable in the previous question, you may enter the net change for any one of your selected sets.
Answer:
Unfavorable reactions: Reaction A and Reaction B.
Coupled reactions favorable: Reactions B and C and Reactions A and C.
Net change:
Reactions B and C : -14.2kJ/mol
Reactions A and B : 30.1kJ/mol
Reactions A and C: -16.7kJ/mol
Explanation:
A reaction is thermodynamically favorable (spontaneous) if ΔG < 0. Thus, the unfavorable reactions -ΔG > 0- are:
Reaction A and reaction B.
When reaction C is coupled with reaction B and reaction A the chemical equation is:
ATP + fructose-1,6-phosphate ⟶ ADP + fructose-1,6-bisphosphate
ΔG = 16.3 - 30.5 = -14.2 kJ/mol
ATP + glucose ⟶ ADP + glucose-6-phosphate
ΔG = 13.8 - 30.5 = -16.7 kJ/mol
The coupled reaction of A and B has a change in free energy of:
ΔG = 13.8 + 16.3 = 30.1 kJ/mol
Please help! BRANLIEST to right answer
Answer:
Endothermic, positive
Explanation:
[HCN]=0.09974 M
Kp=7.52
Calculate the partial pressure of HCN ?
Answer:
i don't understand
Explanation:
What will happen if ultraviolet light shines on metal
Answer:
if this doesnt help then im sorry...
Explanation:
When light is shined on certain metals, electrons may be knocked off the metal. This is called the photoelectric effect. By assuming that light is quantized, Einstein was able to explain the photoelectric effect. ... When UV light of a long wavelength and low frequency is shined on the zinc nothing happens.
Ah yay! Something I can answer.
Answer:
When UV light is shined upon certain metals something called the photoelectric effect occurs. The photoelectic effect is when electrons are discharged from the metal.
Explanation:
Metals contain many electrons and when the electrons are given enough energy they can leave the metal. The electrons that escape the metal are called photoelectrons; hence why this effect is called the photoelectic effect.
At what temperature will a gas be, if you allow it to expand from its original volume of 756 mL at 65.0 °C to 1.40 L? (hint volume needs to be the same)
Answer:
120.4 gradius Celcius
Explanation:
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
What is another term for anode?
Answer:positive electrode
Explanation:
Anode can also be referred to as positive electrode in a cell
Nikolas, the fire extinguisher, and the skateboard have a combined mass of 50 kg. What force would the fire extinguisher have to produce to propel nikolas if he wanted to accelerate at a rate of 1.2 m/s squared
Answer:
Force used by fire extinguisher = 60 N
Explanation:
Given:
Mass of skateboard with fire extinguisher = 50 kg
Acceleration of fire extinguisher = 1.2 m/s²
Find:
Force used by fire extinguisher = ?
Computation:
⇒ Force = Mass × Acceleration
⇒ Force used by fire extinguisher = Mass of skateboard with fire extinguisher × Acceleration of fire extinguisher
⇒ Force used by fire extinguisher = 50 kg × 1.2 m/s²
⇒ Force used by fire extinguisher = 60 N
Answer:
Force=60 N
Hope this helps ya'll!
When a gas particle changes phase into a liquid particle:
A. the particle loses energy
B. the particle gains energy
C. the particle has no change in energy
D. the change in energy depends on the type of gas
Answer:B
Explanation:
The movement in particles is faster than the particle movement in a solid and the attractive forces are much weaker.A gas is something with no definite volume and no definite shape. Gas particles are far apart and move rapidly and freely. The attractive forces between gas particles are very weak or absent.When a liquid is heated, the particles are given more energy. They start to move faster and further apart. At a certain temperature, the particles break free of one another and the liquid turns to gas. This is the boiling point.Particles in gas are well separated with no regular arrangement. liquid are close together with no regular arrangement. Solid are tightly packed, usually in a regular pattern.2. What happens to the pH when you add more H+ ions to a solution that has no buffers?
it takes 26.23 mL of a 1.008 M NaOh solution to neutralize a solution of an unknown monoprotic acid in 150.2 mL of solution. What is the molarity of the unknown?
Answer:
.176 M
Explanation:
set the number of moles of the base equal to the number of moles of acid.
(1.008 mol/L)(26.23 x 10^-3 L)=(150.2x10^-3 L)(x)
x = .176030892 mol/L
Which factor would slow down a chemical reaction? (Choose all that apply)
A)Adding an inhibitor
B)Decreasing temperature
C)Decreasing particle size
D)Increasing particle size
Answer:
(decreasing particle size) C
Explanation: That is one of the answers, if there are more I am sorry.
1. A substance that gets dissolved to create a solution is best described as to
as
Answer:
Solute
Explanation
A substance that gets dissolved to create a solution is best described as to as
what is the reaction?
Answer:
A chemical reaction is a process in which one or more substances, also called reactants, are converted to one or more different substances, known as products. ... A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.
Explanation:
Hopefully this is what you needed
6. Bacteriorhodopsin is an integral membrane protein that uses solar energy (absorbed by its retinal chromophore) to pump protons out of the cell against an electrochemical gradient. Re-entry of the protons into the cell (down the gradient through its ATPase) is then used to drive the synthesis of ATP from ADP and Pi. Consider the following conditions: intracellular pH is 9.4 and extracellular pH is 6.4, and there is a transmembrane electrical gradient of 120 mV (negative inside). The concentration of intracellular [ATP] = 1 mM, [ADP] = 50 µM, and [Pi] = 2 mM, and G° for ATP hydrolysis is -30.5 kJ/mol. Temperature is 27 °C. a. What is the energy cost of pumping one mole of H+ out of the cell? b. What is the minimal number of H+ that must re-enter the cell through the ATPase to provide sufficient energy to synthesize each ATP? Explain how you arrived at this answer quantitatively, of course.
Answer:
Explanation:
Hello!
a)
You have an integral membrane protein (Bacteriorhodopsin) that uses solar energy to pump protons out of the cell against its electrochemical gradient.
To calculate the energy needed by the protein to pump one molecule out of the cell you need to apply the free energy difference equation for a charged molecule:
ΔG= 2.303RTlog₁₀[tex](\frac{[H^+]out}{[H^+]in})[/tex]+zFΔV
Where
ΔG= free energy difference per molecule transferred from the inside to the outside
R= gas constant 8.315*10⁻³ kJ/mol
T= Temperature in Kelvin (273.15 + TºC)
z= Valency of the ion (ej Na⁺ is z= +1 and Cl⁻ is z= -1)
F= Faraday constant 96.5 kJ/V*mol
ΔV= membrane potential (Volts)
The information you have is:
Intracellular pH= 9.4
Extracellular pH= 6.4
ΔV= 120 mV
Temperature 27ºC
Using the values of pH you can calculate the intracellular and extracellular proton concentrations:
Remember the pH of a solution is calculated as pH=-log[H⁺] so if you reverse the logarithm, you'll find the concentration of protons:
b= logₐ C ⇒ C= aᵇ
[H⁺]intracelular= 10⁻⁹'⁴
[H⁺]extracelular= 10⁻⁶'⁴
Now you need to match the units of the temperature and electrical gradient to the ones in the equation:
The temperature needs to ve in Kelvin: T= 273.15 + 27ºC= 300.15K
The electrical gradients need to be in Volts: ΔV= 120 mV= 0.12V
Now you can replace the data in the formula and calculate how much energy is needed to pump one proton outside the cell:
ΔG= 2.303RTlog₁₀[tex](\frac{[H^+]out}{[H^+]in})[/tex]+zFΔV= 2.303*( 8.315*10⁻³ kJ/mol)*300.15K*log[tex](\frac{10^{-6.4}}{ 10^{-9.4}} )[/tex]+(+1)*96.5 kJ/V*mol*0.12V= 28.82 kJ/mol
It costs 28.82 kJ/mol to pump one mole of H⁺ outside the cell.
b)
To synthesize one molecule of ATP the ATP synthase uses the electrical gradient produced by the spontaneous pass of protons through the membrane. This process is called the proton-motive force.
The ATP synthase consists of two subunits F₀ and F₁ with a rotational motor mechanism that allows it to produce and release ATP.
F₁ has the subunits α, β, σ, γ, ε in charge of synthesizing ATP
F₀ is a proton pore, made of 3 subunits a, b and c. 6 subunits c make up the transmembrane ring in charge of rotation, this ring is connected to the subunits γ and ε. Each time a proton passes, it makes the ring rotate which makes the subunits γ rotate.
Each time the subunit γ rotates 360º, 3 ATP molecules are synthesized and freed. A full rotation of γ means that the c-ring also made a full rotation (for this you need one proton per subunit)
If the ring has 6 c-subunits and, then each ATP molecule needs 6/3= 2 protons to need to pass for each ATP molecule.
I hope this helps!
