ABSTRACT
This chapter describes the constituents of atoms, including nuclei comprising protons and neutrons, surrounded by clouds of electrons. The concepts of atomic number, mass number, nuclides, isotopes, ions, and molecules are described, as well as solids, liquids, and gases. It next describes the physics of motion, including concepts of distance, displacement, speed, velocity, acceleration, linear momentum, angular velocity, angular momentum, force, weight, pressure, and torque. Newton’s laws of motion and Noether’s theorem linking conservation laws with symmetries are described. Ideas of relativistic motion resulting from Einstein’s special theory of relativity are considered, including time dilation, length contraction, simultaneity, and causality. The concept of energy is discussed next including kinetic energy, various forms of potential energy (including gravitational and electrical energy), the idea of mass–energy equivalence, annihilation and pair creation, and the concepts of power, work, and heat. The unit of the electronvolt is introduced as being relevant to the energy of atomic processes. Finally, the physics of light, emission, and absorption line spectra, and the electromagnetic spectrum is described, including concepts of wavelength and frequency, radio waves, microwaves, infrared and ultraviolet radiation, X-rays, and gamma-rays. The photon model of electromagnetic radiation is also presented.
