Huygens thought light travels as waves, while Newtonbelieved it travels as particles. = c/ = frequency (s1, Hz, cyc/s, or waves/s ) = wavelength (m)c = speed of light (m/s) Wavelength and frequency can be interconverted. WavesWaves have 3 primary characteristics:1.Wavelength: distance between two peaks in a wave.2.Frequency: number of waves per second that pass a given point in space.3.Speed: speed of light is 2.9979 108 m/s.Īs the wavelength () decreases, the frequency () increases. Similarity of ElementsElements are grouped together in vertical columns (Groups) that have similar properties.Alkali Metals - Li, Na, K, Rb, & CsHalogens - F2, Cl2, Br2, & I2Noble Gases - He, Ne, Ar, Kr, Xe, & RnĮlectromagnetic RadiationRadiant energy that exhibits wave-like behavior and travels through space at the speed of light in a vacuum.Įlectromagnetic RadiationwavelengthVisible lightwavelengthUltraviolet radiationAmplitudeNode +ElectronorbitOne view of atomic structure in early 20th century was that an electron (e-) traveled about the nucleus in an orbit.
Modern View of the AtomTiny, dense, positively charged nucleus made up of positive protons and neutral neutrons.Negatively charged electron shells enclose the nucleus and contain negative electrons.Ītomic Spectra and Bohr1.Any orbit should be possible and so is any energy.2.But a charged particle moving in an electric field should emit energy. Atomos is the Greek word for indivisible.
, Aristotle thought all matter was made of four elements :earthairfire waterĪNCIENT GREEKS VIEW OF MATTERAt about the same time another Greek philosopher, Democritus, said that matter was made of tiny, indivisible particles called atoms. ANCIENT GREEKS VIEW OF MATTERAbout 400 B.C.