Question

To verify conservation in the proton-proton cycle (2e⁻ + 4¹H → 4⁴He + 2nuₑ + 6γ), list the quantities before and after the cycle:

a) Nucleons: Before = 4, After = 4; Charge: Before = 0, After = 0; Electron Family Number: Before = 2, After = 2
b) Nucleons: Before = 4, After = 4; Charge: Before = 2e, After = 2e; Electron Family Number: Before = 2, After = 2
c) Nucleons: Before = 2, After = 2; Charge: Before = 0, After = 0; Electron Family Number: Before = 4, After = 4
d) Nucleons: Before = 2, After = 2; Charge: Before = 2e, After = 2e; Electron Family Number: Before = 4, After = 4

Answer 1

The conservation in the proton-proton cycle is proven by showing that the number of nucleons, the total charge, and the electron family number remain unchanged before and after the reaction. The correct option is (b): Nucleons: Before = 4, After = 4; Charge: Before = 2e, After = 2e; Electron Family Number: Before = 2, After = 2.

Step-by-step explanation:

To verify conservation in the proton-proton cycle (2e- + 41H → 44He + 2nue + 6γ), we can list the quantities of nucleons, charge, and electron family number before and after the cycle to demonstrate that these quantities are conserved:

• Nucleons: Before = 4 protons (4 hydrogen nuclei), After = 1 helium nucleus (2 protons and 2 neutrons, total 4 nucleons)
• Charge: Before = the charge of 4 protons (4 positive charges), After = the charge of 1 helium nucleus (2 positive charges due to the 2 protons, the same as before when considering the 2 positrons that are annihilated are also included in the after)
• Electron Family Number: Before = 2 (because of the 2 electrons), After = 2 (due to the 2 neutrinos)

Therefore, the correct option listing the conserved quantities would be option (b):

• Nucleons: Before = 4, After = 4
• Charge: Before = 2e, After = 2e
• Electron Family Number: Before = 2, After = 2