Absolute zero. Zero kelvin (â273.15 Â°C) is defined as absolute zero. Absolute zero is the lower limit of the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reaches its minimum value, taken as 0. Absolute zero is the point at which the fundamental particles of nature have minimal vibrational motion, retaining only quantum mechanical, zero-point energy-induced particle motion. The theoretical temperature is determined by extrapolating the ideal gas law; by international agreement, absolute zero is taken as ...
The nuclear spins for individual protons and neutrons parallels the treatment of electron spin, with spin 1/2 and an associated magnetic moment. The magnetic moment is much smaller than that of the electron. For the combination neutrons and protons into nuclei, the situation is more complicated.
1.9: Understand that atoms consist of a central nucleus, composed of protons and neutrons, surrounded by electrons, orbiting in shells. The nucleus of the atom contains protons and neutrons. The nucleus is orbited by a number of electrons in a number of shells. The following diagram has only one shell of electrons: