 Fusion – process of 2 nuclei that combine to make one (a new element ) and emitting large amounts of energy.  The sun is a giant ball of hydrogen gas undergoing a fusion reaction – releasing energy.  We know that energy as electromagnetic radiation

 White light contains all visible light spectrum  RO Y G B V  We see….  Black – absorbing all colors  White – reflecting all colors  Color – ex: red – reflecting red and absorbing all other colors

 Example – sun light  Passes through prism & separates into continuous spectrum.  Called continuous because all portions are visible – no blank areas

 All electrons in an atom exist naturally in their “ground state” e- configuration (all want to be close to nucleus – lower in energy)  If energy is added – electrons move to higher energy level – “excited state” – but don’t stay.  Electrons fall back to ground state and release light

 An electron will jump to a higher energy level by absorbing energy.  An electron will fall back to ground state by releasing light 

 Element’s atomic emission spectra is unique - used to determine an unknown compound.  Like a fingerprint  All elements have a different atomic emission spectrum  Found by using a spectroscope.

 Instrument designed to visually observe spectra by splitting the LIGHT into its components.  Usually has PRISM or a DIFFRACTION GRATING to split light into components.  Diffraction gratings consist usually of thousands of narrow, closely spaced parallel slits (or grooves).

Continuous Spectrum Emission Spectrum Absorption Spectrum

continuous emission absorption

Hydrogen spectrum Helium spectrum The light of the gas is split into its components or an emission spectrum