5. transition metals

• What is the significance of d-block elements in the periodic table?


  They are the transition metals
• How many transition elements are there in period four?

  Eight transition elements
• What defines a transition element?

  Forms a stable ion with a partially filled d subshell
• What is the maximum number of electrons a d subshell can hold?

  Ten electrons
• Why are scandium and zinc not considered transition elements?

  They do not form stable ions with partially filled d subshells
• How do electrons fill orbitals in transition metals?

  They fill singly before pairing up
• What analogy is used to explain electron filling in orbitals?

  Seating on a bus
• What is the electron configuration of argon?


  1s2 2s2 2p6 3s2 3p6
• What happens to the electron configuration of chromium?

  One electron from 4s jumps to 3d
• Which two elements behave differently in electron configuration?

  Chromium and copper
• What is the stable configuration for chromium?

  Half-full 3d subshell
• What is the only stable ion that scandium forms?

  Scandium three plus
• Why is zinc not a transition element?

  It has a full d subshell in its ion
• How do electrons get removed to form ions in transition metals?

  From the 4s orbital before the 3d
• What is the electron configuration of iron?

  1s2 2s2 2p6 3s2 3p6 3d6 4s2
• What is the electron configuration of iron three plus?

  3d5
• How can you verify the electron configuration of iron three plus?

  By checking the total number of electrons
• What are the key properties of transition metals?

  • Form stable ions with partially filled d subshells
  • Exhibit variable oxidation states
  • Act as catalysts in reactions
  • Often colorful in compounds
• What is the process of electron configuration in transition metals?

  1. Electrons fill orbitals singly first.
  2. Pairing occurs only after all orbitals are occupied.
  3. Electrons prefer lower energy states.
  4. Special cases: Chromium and copper have unique configurations.
• What distinguishes transition metals from other d-block elements?

  • Transition metals can form stable ions with partially filled d subshells.
  • Other d-block elements (like scandium and zinc) do not meet this criterion.
• What is the atomic number of iron?

  26
• How many electrons does iron lose to form iron three-plus?

  Three electrons
• What is the electron configuration of iron three-plus?

  Partially filled 3d subshell
• Why are transition metals significant in terms of electron configurations?

  They have variable oxidation states
• What are the properties of transition metals?

  • Variable oxidation states
  • Form colored ions in solutions
  • Act as good catalysts
• Which elements are not considered transition metals?

  Zinc and scandium
• What colors do vanadium ions exhibit in different oxidation states?

  Violet, green, blue, yellow
• What color is chromium three-plus in solution?

  Green
• What is the color of manganese two-plus ions?

  Pink
• What color is iron two-plus in solution?

  Pale green
• What color is cobalt two-plus in solution?


  Pink
• What color is copper two-plus in solution?

  Blue
• What defines a complex ion in transition metals?

  • Central transition metal ion
  • Surrounded by ligands
  • Bonded by dative covalent bonds
• What is a ligand?

  An atom with at least one lone pair
• What are the types of ligands based on electron pairs?

  • Monodentate ligands: One lone pair
  • Bidentate ligands: Two lone pairs
  • Polydentate ligands: Multiple lone pairs
• What are three examples of monodentate ligands?

  Water, ammonia, chloride ion
• What is an example of a bidentate ligand?

  Ethanediamine
• What is an example of a polydentate ligand?

  EDTA
• How does ligand size affect complex ion shape?

  • Smaller ligands allow more around metal
  • Larger ligands limit number around metal
• What is the coordination number in a complex ion?

  Number of coordinate bonds