QUARTER 2

• Who proposed the Solid Sphere Model?

  John Dalton
• What is the Solid Sphere Model based on?

  Experimental evidence and quantitative observations
• Who is known for the Plum Pudding Model?

  J.J. Thomson
• What did J.J. Thomson discover?

  Electrons as distinct particles
• Who introduced the Nuclear Model?

  Ernest Rutherford
• What does the Nuclear Model propose?

  A central, massive nucleus exists
• What experiment explained the behavior of alpha particles?

  The gold foil experiment
• How did Rutherford's work contribute to atomic structure understanding?

  Laid groundwork for understanding atomic structure
• Who proposed the Planetary Model?

  Niels Bohr
• What concept did Niels Bohr introduce?

  Quantized energy levels
• Who proposed the Quantum Model?

  Erwin Schrodinger
• What does the Quantum Model describe about electrons?

  Electrons exist as a wave-like pattern
• What does the principal quantum number (n) indicate?

  Main energy level or shell of the orbital
• What values can the principal quantum number (n) have?


  1, 2, 3, and so on
• What does the angular momentum quantum number (l) describe?

  Shape of the orbital
• What values can the angular momentum quantum number (l) have?

  0 to n-1
• What does the magnetic quantum number (ml) describe?

  Orbital orientation
• What values can the magnetic quantum number (ml) have?

  -l to +l
• What does the spin quantum number (ms) indicate?

  Electron spin direction
• What values can the spin quantum number (ms) have?

  +1/2 and -1/2
• What is an electron?

  A particle with an electric charge
• What are valence electrons?

  Electrons in the outermost energy level
• What does valence refer to in chemistry?

  Capacity of atoms to form bonds
• What does electron configuration indicate?

  Arrangement of electrons in an atom
• How is the number of valence electrons determined for representative elements?

  Equal to total electron population at highest level
• What does the Lewis Electron-Dot Structure represent?

  Valence electrons and atomic nucleus
• What are the general rules for drawing Lewis dot structures?

  1. Draw only valence electrons
  2. Main group elements (except H, Li, Be) want an octet
  3. H, Li, and Be are stable with 2 electrons (duet)
• What is ionization energy?

  Energy required to remove an electron
• What is electron affinity?

  Energy released or absorbed when adding an electron
• What is electronegativity?

  Ability to attract electrons in a bond
• What does the Octet Rule state?

  Atoms bond to have eight electrons in valence shell
• How can atoms obtain an octet?

  • Metals lose electrons to form cations
  • Nonmetals gain electrons to form anions
  • Atoms share electrons to complete octet
• What enables ionic bonding?

  Lower electron affinity and ionization energy of metals
• How do nonmetals bond in covalent bonding?

  By sharing electrons to complete octet
• What is an ionic bond?

  Formed when an atom gains or loses an electron
• What is a cation?

  A positive ion
• What is an anion?

  A negative ion
• What is electron transfer?

  Process of one atom losing an electron
• What is a crystal lattice?

  Arrangement of alternating positive and negative ions
• What are the properties of ionic compounds?

  1. High melting and boiling points
  2. Do not conduct electricity in solid state
  3. Hard and brittle