Electrons + Bonding

Electrons + Bonding

1. Filling electron orbitals

   • Electron spins always OPPOSITE directions
   • Occupy sub-shell orbitals with one electron each first
     • Electrons want to be as far away from each other as possible, increases stability
   • Order of filling 1-4, s-p-d-f
     • 4s before 3d
       • Cu and Cr exceptions
         • 4s1, 3d5/10
   • Electrons leave from highest energy shell

2. Orbitals

   • S
     • Spherical
       • 1 orbital, 2 electrons
   • P
     • Dumbbell shaped
     • 3 orbitals, 6 electrons
   • D
     • 5 orbitals, 10 electrons
   • F
     • 7 orbitals, 14 electrons

3. Proton number

   • Atomic Radius
     • Electron Shielding

4. Across a period

   • Increases
     • Decreases
       • Remains Constant

5. Down a group

   • Increases
     • Increases
       • Increases

6. 1st ionisation energy

   • Nuclear Attraction
   • Energy required to remove 1 electron per atom in a mole of gaseous atoms...
   • n electrons, n ionisation energies

7. Bonding

   • IONIC
     • Melting points
       • High
       • Increase with larger charges
       • Decrease down group, bigger ions, less charge dense
     • Conductivity
       • Solid- not conductive, ions held into place. Liquid- conductive, ions free to move + carry charge
     • Solubility
       • Many soluble in POLAR solvents which break down ionic lattice
       • Ionic attraction often too strong for water, less soluble
     • Electrostatic attraction between negative and positive ions
   • COVALENT
     • Giant lattice
       • Non conductors- no free/charged particles. EXCEPT GRAPHINE + GRAPHITE (delocalised electron pool)
       • Very High mpt and bpt, strong bonds as both nuclei attracted to same points
       • Simple molecular
         • Low mpt/bpt - weak IMF
     • Electrostatic attraction between shared pair of electrons and nuclei of bonded atoms
     • Dative bonds- both bonding electrons from ONE atom, not ideal
   • METALLIC
     • Melting + Boiling points
       • Mostly high
       • Down group- decrease, ions bigger so less charge dense
       • Across period- increase, charges larger and more delocalised electrons
     • Conductivity- high in solids + liquid as delocalised electrons free to move and carry a charge
     • Electrostatic forces between positive metal ions and delocalised electrons
     • Solubility- insoluble, interactions with water cause reactions

8. REMEMBER: Large jumps show shell change Make sure jumps steep

Imagens e arquivos do mapa