Baryons are a group of elementary particles. The heavier particles such as protons and neutrons belong to these baryons. Usually a baryon is made of three quarks; the more exotic ones consist out of four quarks and one anti-quark. [Don't Panic]

When a group of spins is placed in a magnetic field, each spin aligns in one of the two possible orientations. The relative numbers of spins with different alignments will be given by the Boltzmann distribution.
Definition: if a system of particles, which are able to exchange energy in collisions is in thermal equilibrium, then the relative number (population) of particles, N1 and N2, in two particular energy levels with corresponding energies, E1 and E2, is given by N1/N2 = exp [-(E1 - E2)/kT ] where k is the Boltzmann constant and T is the absolute temperature. For example, in NMR of protons at room temperature in a magnetic field of 0.25 tesla, the difference in relative numbers of spins aligned with the magnetic field and against the field is about one part in a million; the small excess of nuclei in the lower energy state is the basis of the net magnetization and the resonance phenomenon.

Coulomb is the SI unit of electric charge. One coulomb is the amount of charge accumulated in one second by a current of one ampere.
The charge of a proton is 1.6 x 10^-19 coulombs. The charge of an electron is - 1.6 x 10^-19 coulombs. An atomic particle has a charge which is an integral multiple of 1.6 x 10^-19 coulombs.

A Deuteron is the nucleus of deuterium, also called heavy hydrogen. It consists of one Proton and one neutron.

An electron is a negatively charged subatomic particle that orbits the positively charged nucleus of an atom and determines chemical properties. The mass of an electron is around 1/1837 that of the proton.

See also Rutherford-Bohr Atom Model, Beta Particle.