In the early universe, which type of particle and anti-particle first stopped being spontaneously formed out of photons in the CMB?
A) Protons and neutrons, because their formation requires a larger number of photons
B) Electrons and positrons, because their formation requires a smaller number of photons
C) Protons and antiprotons, because their formation requires higher energy photons
D) Electrons and neutrinos, because their formation requires lower energy photons
E) Protons, antiprotons, electrons, and neutrinos stopped forming at the same time.

Question

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The Answer of In the early universe, which type of particle and anti-particle first stopped being spontaneously formed out of photons in the CMB?
A) Protons and neutrons, because their formation requires a larger number of photons
B) Electrons and positrons, because their formation requires a smaller number of photons
C) Protons and antiprotons, because their formation requires higher energy photons
D) Electrons and neutrinos, because their formation requires lower energy photons
E) Protons, antiprotons, electrons, and neutrinos stopped forming at the same time.

In the Early Universe, Which Type of Particle and Anti-Particle