play phryzby with physics

Two Carbon Nuclei Fusing

solved MassEnergy

Q. The Q value of a nuclear reaction A + b → C + d is defined by Q = [mA + mb – mC – md]c², where the masses refer to the respective nuclei. Given m(¹²₆C) = 12.000000 umc=12.000000u, m(²⁰₁₀Ne) = 19.992439 umn=19.992439u and m(⁴₂He) = 4.002603 umh=4.002603u, what is the Q-value of the reaction ¹²₆C + ¹²₆C → ²⁰₁₀Ne + ⁴₂Hedmr=2⋅mc-mn-mh, in MeV?

2×carbonm = 12 uneonm = 20 u+heliumm = 4 uQ = ?Δm
Inputs
mc
12 u
mn
19.99 u
mh
4.003 u
Outputs
qQr?

How it's solved

Solved with MassEnergy

Given

  • mc=12.000000u
  • mn=19.992439u
  • mh=4.002603u
  • dmr=2⋅mc-mn-mh from “¹²₆C + ¹²₆C → ²⁰₁₀Ne + ⁴₂He”

Find Qr.

Working
  1. mc=12.000000u=1.99264688×10−26kg
  2. mn=19.992439u=3.3198226×10−26kg
  3. mh=4.002603u=6.64647865×10−27kg
  4. ¹²₆C + ¹²₆C → ²⁰₁₀Ne + ⁴₂Hedmr=2⋅mc-mn-mh
  5. dmr=2⋅1.99264688×10−26-3.3198226×10−26-6.64647865×10−27
  6. dmr=8.23295269×10−30kg
  7. energy a reaction gives out(reaction)Qr=dmr⋅c2
  8. Qr=8.23295269×10−30⋅(2.99792458×108)2
  9. Qr=4.618MeV
  10. Qr=7.39940887×10−13J=4.61834776MeV
  11. Qr≈4.62MeVto 3 significant figures
Conclusion

The neon and helium nuclei weigh less than the two carbon nuclei, and the lost mass comes out as energy: the reaction is exothermic.

The web of concepts

given read from the words equation asked

The Ruby that solves it

The question and its solution are small Ruby files. The engine runs them.

question.rb
1require_relative "../physics"23question :two_carbon_nuclei_fusing do4  kind :numerical5  describes "The Q value of a nuclear reaction A + b → C + d is defined by Q = [mA + mb – mC – md]c², where the " \6            "masses refer to the respective nuclei. Given m(¹²₆C) = %{carbon}, m(²⁰₁₀Ne) = %{neon} and " \7            "m(⁴₂He) = %{helium}, %{q} of the reaction ¹²₆C + ¹²₆C → ²⁰₁₀Ne + ⁴₂He, in MeV?"8  given carbon: "12.000000 u"9  given neon: "19.992439 u"10  given helium: "4.002603 u"11  asks q: "what is the Q-value"12end
solution.rb
1require_relative "../questions/two_carbon_nuclei_fusing"2require_relative "../science/nuclei/mass_energy"34solve :two_carbon_nuclei_fusing, using: MassEnergy do5  objects :reaction, :carbon, :neon, :helium67  take carbon: carbon.mass8  take neon: neon.mass9  take helium: helium.mass1011  deduce_from "¹²₆C + ¹²₆C → ²⁰₁₀Ne + ⁴₂He",12              reaction.mass_defect => 2 * carbon.mass - neon.mass - helium.mass1314  q = reaction.q_value15  answer q:, in: "MeV", figures: 31617  conclusion "The neon and helium nuclei weigh less than the two carbon nuclei, and the lost mass comes out as " \18             "energy: the reaction is exothermic."19end
playground.rb
1require_relative "../solutions/two_carbon_nuclei_fusing"23play_with :two_carbon_nuclei_fusing do4  title "Two Carbon Nuclei Fusing"5end
The laws it drew on
quantitywrittenunitswithinfrom
speed of lightcm/s—MassEnergy
hydrogen atom massmHkg—MassEnergy
neutron massmnkg—MassEnergy
massmkg0 … ∞MassEnergy
energyEJ—MassEnergy
atomic numberZ——MassEnergy
mass numberA—0 … ∞MassEnergy
mass defectdmkg—MassEnergy
binding energyEbJ—MassEnergy
q valueQJ—MassEnergy
energy of groundEgJ—
mass of groundmgkg0 … ∞
energy of reactionErJ—
mass of reactionmrkg0 … ∞
energy of carbonEcJ—
mass of carbonmckg0 … ∞
energy of neonEnJ—
mass of neonmnkg0 … ∞
energy of heliumEhJ—
mass of heliummhkg0 … ∞
mass defect of grounddmgkg—
atomic number of groundZg——
mass number of groundAg—0 … ∞
mass defect of reactiondmrkg—
atomic number of reactionZr——
mass number of reactionAr—0 … ∞
mass defect of carbondmckg—
atomic number of carbonZc——
mass number of carbonAc—0 … ∞
mass defect of neondmnkg—
atomic number of neonZn——
mass number of neonAn—0 … ∞
mass defect of heliumdmhkg—
atomic number of heliumZh——
mass number of heliumAh—0 … ∞
binding energy of groundEb,gJ—
binding energy of reactionEb,rJ—
binding energy of carbonEb,cJ—
binding energy of neonEb,nJ—
binding energy of heliumEb,hJ—
q value of groundQgJ—
q value of reactionQrJ—
q value of carbonQcJ—
q value of neonQnJ—
q value of heliumQhJ—
Eb=mb⋅c2
einsteins mass energy
dmn=Zn⋅mH+(An-Zn)⋅mn-mn
mass lost in binding
Eb,n=dmn⋅c2
energy of the lost mass
Qr=dmr⋅c2
energy a reaction gives out
Eg=mg⋅c2
einsteins mass energy(ground)
Er=mr⋅c2
einsteins mass energy(reaction)
Ec=mc⋅c2
einsteins mass energy(carbon)
En=mn⋅c2
einsteins mass energy(neon)
Eh=mh⋅c2
einsteins mass energy(helium)
dmg=Zg⋅mH+(Ag-Zg)⋅mn-mg
mass lost in binding(ground)
dmr=Zr⋅mH+(Ar-Zr)⋅mn-mr
mass lost in binding(reaction)
dmc=Zc⋅mH+(Ac-Zc)⋅mn-mc
mass lost in binding(carbon)
dmn=Zn⋅mH+(An-Zn)⋅mn-mn
mass lost in binding(neon)
dmh=Zh⋅mH+(Ah-Zh)⋅mn-mh
mass lost in binding(helium)
Eb,g=dmg⋅c2
energy of the lost mass(ground)
Eb,r=dmr⋅c2
energy of the lost mass(reaction)
Eb,c=dmc⋅c2
energy of the lost mass(carbon)
Eb,n=dmn⋅c2
energy of the lost mass(neon)
Eb,h=dmh⋅c2
energy of the lost mass(helium)
Qg=dmg⋅c2
energy a reaction gives out(ground)
Qr=dmr⋅c2
energy a reaction gives out(reaction)
Qc=dmc⋅c2
energy a reaction gives out(carbon)
Qn=dmn⋅c2
energy a reaction gives out(neon)
Qh=dmh⋅c2
energy a reaction gives out(helium)
dmr=2⋅mc-mn-mh
¹²₆C + ¹²₆C → ²⁰₁₀Ne + ⁴₂He