Atomic Physics Dimitri Mendeleev Physics 100 Chapt 24

Atomic Physics Dimitri Mendeleev Physics 100 Chapt 24

Periodic table of elements Inert gasses Elements in vertical rows have similar chemical properties

Schroedinger’s Equation for multielectron Atoms + - -

Allowed energy levels are clustered in “shells” - - + - - n # of states - - 1 2 2 8 3 a 8 3 b 10 4 a 8 4 b 10 4 c 14

Pauli exclusion principle Wolfgang Pauli Only one electron per quantum state Once a quantum state is occupied additional electrons are excluded

Light elements +1 - 1 electron in Hydrogen outermost shell - - +3 Lithium - outermost shell is full - +2 - Helium - - +10 - - Neon

Periodic table of elements Filled outer shell 1 e- in outer shell Elements in vertical rows have similar chemical properties

Chemical properties depend upon the outermost shell configuration - - - +8 - - Oxygen Outermost shells Have 2 vacancies - - - +16 - - Sulfur -

2 vacancies in outer shell Periodic table of elements

Atoms combine to form molecules by filling outer shells Hydrogen Water=H 2 O Hydrogen +1 - - +8 - - +1 Oxygen

Atoms combine to form molecules by filling outer shells Hydrogen +1 Methane=CH 4 Hydrogen - - +1 - +6 - - - +1 +1 Carbon Hydrogen

Elements with full outer shells don’t form molecules - - - +2 - Helium - - -+10 +18 - - - Neon - - Noble gasses Argon

Periodic table revisited Outer shell is full 2 vacancies in outer shell 4 e- in outer shell 1 elec in outer shell Elements in vertical rows have same outer shell configurations