Weak interactions transforming protons to neutrons or vice versa were considered in terms of developed polaronic exciton concept and chemical physics. The suggested model describes events of neutron β-decay and the spectrum and explains why free neutron is the most long-lived among the other meta-stable particles. Gas-phase water as the environment for the β-decay reaction mimicking that in Earth atmosphere implies that neutron β-decay occurs under mediation of hydrogen-bonded water molecules since neutron hydration is impossible to avoid because water forms clusters even at high vacuum. Proton sharing frequency of 3.45238 ± 0.01016 THz found earlier in the hydrogen-bonded molecules of water clusters generates the charge oscillations. The oscillation or microwave photon absorption produces energy gap between 2S_1/2 and 2P_1/2 electron levels in the hydrated neutron generating a meta-stable state. An estimate of the energy gap and the consideration of neutron β-decay events allowed to calculate neutron lifetime that is found to be 882.118 s. The latter is in a good agreement with averaged neutron lifetime of 881.5 ± 1.5 s. The energy gap estimation allowed to conclude that the spectrum of cosmic microwave background radiation corresponding to that of blackbody radiation originates under neutron creation from strongly coupled opposite charges located on the oxygen atom of hydrogen-bonded water molecule. Distribution of kinetic energy of the electrons glued with antineutrino emitted under neutron β-decay is found consistent with the measured β-decay spectrum.