4.3 Notes Revise 08

Theory Section 4-3 Bohr’s Model Electron Cloud Atomic Orbitals Electron Configuration

Bohr’s Model • Focus on Electron • Electrons exist in specific fixed orbits around the nucleus • Electrons change orbitals if the atom gains or losses energy

Evidence for Energy Levels Sodium

• The amount of energy a Electron absorbs Li can be measured • When releasing energy or moving to a lower orbital electrons give off light

Evidence for Energy Levels: Spectral Lines

Cu

Li B

Sodium

Electron Cloud • Electron cloud is a visual model that shows the most likely location of the electron • The electron constantly moves around the nucleus

Atomic Orbitals • An orbital is the region of space around the nucleus where the electron can be found • Orbitals are approximations of how electrons behave in their orbitals (probability)

Electron Configuration • The arrangement of electrons in their orbitals • The most stable econfig. is when the e- are in their lowest energy state. (ground state)