Chemistry Concept Map

Chemistry Concept Map

1. Atomic Theory and Nuclear Model

   • Protons and Electrons
     • Rutherford presented change that Atom was a uniform sphere that had two distinct areas
       • Positive charge (protons) contained in the nucleus
       • Surrounding outer negative electron field
   • Neutrons
     • Location inferred through release of an uncharged, slow moving particle from nucleus
   • Atomic Number
     • Mosely showed that each element had a unique number of protons
       • Determined through experimentation involving radiation bombardment in nucleus of an atom
       • The two scientists discovered these changes and trends by measuring deflection of rays off of atoms
       • Atomic Number
   • Isotopes
     • Soddy’s analysis of the non constant increase in atomic mass lead to conclusion
       • Soddy’s analysis is a direct expansion off of Mosely’s discovery of increasing atomic number
         • Was looking for a similar increasing pattern involving mass
       • Same elements can have different neutron numbers

2. Periodic Trends

   • Electron Affinity
     • BR model couldn't explain disrupted trend in EA
       • Family 4 more accepting of e than predicted
       • Family 5 less accepting than predicted
         • Partially stable=balanced forces
           • Movement of e to higher adjacent sublevel
   • Ionization energy
     • Sudden large increase in Ionization Energy indicate removal of electrons from lower energy levels
     • The further an electron is from the nucleus, the easier it is to remove
       • Larger atom=more shielding and lower IE
   • Atomic Size
     • Each addition of a level made atoms larger than expected
       • FR from shielding between electron levels increased size of atoms going down families
     • The further an electron is added from the nucleus, less energy is released
       • More shielding between electrons in shells
       • Decreases going down family
         • FR outweighs

3. Quantum Model

   • Orbitals
     • Repulsive Pairing
     • Stability=full orbitals
       • Cancels magnetic forces of electrons
   • Sublevels
     • Specific e location
     • Filled according to Aufbau's principle
   • Repulsion
     • Min. if orbitals within sublevel fill 1 e at time before pairing
   • Stability
   • Promotion

4. Bohr Rutherford

   • Line Spectra
     • Based on Hydrogen
   • Energy Levels (Shells)
     • BR Model used line spectra to conclude location of electrons in energy levels
       • Max electrons per shell= 2n^2
       • Due to release of energy between levels
   • BR model couldn't explain disrupted trend in increasing IE
     • Harder to remove electron from family 2 & 5
       • Higher IE
   • Features of the quantum model helped account for anomilies seen through peridic trends according to BR model