Elements of Special Theory of Relativity. Planck's theory of blackbody radiation. Energy quantization. Photons. Photoelectric effect. Compton effect. Pair production. Rutherford scattering. The atomic models of Rutherford and Bohr. Atomic spectra. Matter waves. Wave-particle duality and the Heisenberg Uncertainty Principle. The Schrödinger equation and interpretation of the wave function. Trapping and tunneling of particles. Quantum numbers of the Hydrogen atom. Angular and magnetic momenta of the electron. Electron spin. Stern-Gerlach experiment. Fine and hyperfine structure. The Pauli's exclusion principle. Multielectron atoms and the periodic table. X-rays. Moseley’s law. Auger electrons. Laser. Molecular bonds. Molecular spectra.