atomic theory II - bohr model of atom

problems with rutherfords planetary model

1. stability of atom

   • charged electron should emit radiation as it orbits, losing energy and collapsing into nucleus

2. line of spectra of elements

   • all elements create a unique color when excited (flame test) due to series of spectral lines each element forms (studied by robert bunsen)

the visible spectrum (hot gas, cold gas, elements)

• white light: consists of continous spectrum

• hot gas: produce emmision line spectrum

• element: emits unique series of lines

• cold gas and white light: produces abosrption line spectrum

neils bohr

• developed a mathematical equation that related energy of each jump of electrons to color of light emmitted

• developed bohrs shells model

bohrs shells model

• electrons only occupy certain orbits/shells/energy levels

• electrons can exist in an energy level without losing energy

• electrons only absorb/release energy when they change levels