CHAPTER A Newtonian Physics description of mechanical events those thatInvolve forces acting on matter using the laws of motion and gravitation The nuclear model of the atom shows that an atom is mostly empty space with electrons orbiting a fixed positively charged Nucleus in set Predictable paths ers Protoen Characterization of electromagnetic radiation a flow of photons AKA light quanta through spare 1 H2 15 C In E In Wavelength spatial period of a periodic wave Frequency number of occurences of a repeating event per unit of time Hz Amplitude displacement of a wave from Zero Intensity the quantity of energy which the wave conveys per unit time across the sur face of the unit area Wavelengths Ultraviolet 10 to 400 nm Visible 400 nm Infrared 700n m X vIf Atomic Spectra Spectrum of the electromagnetic radiation emitted or absorbed by an electron during transitions between different energy levels within an atom Emission has different colored lines in the spectrum Absorbtion has dark colored lines