mtaarers

• Electron


  • Subatomic particles with a NEGATIVE CHARGE
  • Not made from smaller components and are found OUTSIDE the Nucleus
  • Mass: 9.10938 x 10-31kg or 1/1836 the mass of a proton
• Importance of electrons

  • Valence & Reactivity
  • Chemical Bonding & Reactions
  • Ion Formation
  • Molecular Structure
  • Electronegativity
  • Chemical Families
  • Chemical Reactivity Trends
  • Material Properties
• Energy Level


  • Shell around an atom's nucleus
  • Principal Quantum No.
  • Max of 32 electrons

  
• Subshell

  • Electron moves within a shell
  • Magnetic Quantum No.
  • Max of 2 electrons

  
• Orbital


  • Wave-like behavior of an atom
  • Angular Momentum Quantum No.
  • Depend on type of Subshell

  
• Rules in electron configuration

  • Pauli Exclusion Principle
  • Aufbau's Principle
  • Hund's Rule
• Pauli Exclusion Principle

  • Orbitals hold a max of 2 electrons
  • Must have opposite signs
• Aufbau's Principle


  Electrons are first placed in the orbitals of the lowest energy and so on
• Hund's Rule


  Every orbital in a sublevel is singly occupied before any orbital is doubly occupied
• Metals

  • Form cations
  • Metallic luster
  • Good conductors
  • Malleable and ductile
  • High melting point
  • Most solid at room temperature
  • Sonorous
• Non-metals


  • Form anions
  • Dull, colorless to colorful
  • Poor conductors
  • Brittle
  • Low melting point
  • Often liquids or gasses at room temperature
  • Not sonorous
• Electron Affinity

  • Release of energy
  • Gain of electrons
• Ionization Energy

  • Absorption of energy
  • Lose of electrons
• Electronegativity


  • Measures how strongly an atom attracts electrons
  • Increases from bottom left to top right

  
• Valence electrons


  The electrons in the outermost shell, or energy level, of an atom
• Octet rule

  • Atoms tend to have 8 electrons on their valence shell
  • Atoms with less or more than 8 electrons participate in chemical bonds to satisfy the rule
  • Only applies to s & p electrons
• Valence Shell Electron Pair Repulsion is used to predict the shape of the molecules from the electron pairs that surround the central atom of the molecule