1 TRANSITION ELEMENTS

• What is a characteristic of the electron configuration of transition elements?

  They have an incomplete d-subshell.
• What does it mean for a transition element to form a stable ion with an incomplete d-subshell?

  It means the element can lose electrons and still maintain stability.
• Which transition elements are exceptions to the rule of forming stable ions with an incomplete d-subshell?

  Scandium and zinc.
• What ion does scandium form and what is its electron configuration?

  Scandium forms the ion Sc3+ with configuration [Ar] 3d0
• What ion does zinc form and what is its electron configuration?

  Zinc forms the ion Zn2+ with configuration [Ar] 3d10
• What is the range of elements in the first transition series?

  The first transition series ranges from titanium to copper.
• What does the Aufbau Principle state regarding electron configuration?

  Electrons occupy the lowest energy subshells first.
• Which subshell is filled before the 3d subshell according to the Aufbau Principle?

  The 4s subshell.
• What are the exceptions to the Aufbau Principle for electron configurations?

  Chromium and copper have unique configurations.
• What is the electron configuration of chromium?

  Chromium is [Ar] 3d5 4s1
• What is the electron configuration of copper?

  Copper is [Ar] 3d10 4s1
• What are the electronic configurations of an iron atom and its common ions?

  • Fe atom: 1s2 2s2 2p6 3s2 3p6 3d6 4s2
  • Fe2+ ion: 1s2 2s2 2p6 3s2 3p6 3d6
  • Fe3+ ion: 1s2 2s2 2p6 3s2 3p6 3d5
• What are the general properties of transition elements?

  • Variable oxidation states
  • Form complex ions
  • Form coloured compounds
  • Behave as catalysts
• How do transition elements differ from other metals in terms of oxidation states?

  They can form more than one positive ion by losing electrons.
• How are oxidation states indicated for transition metals?

  Roman numerals indicate the oxidation state on the metal ion.
• What is a complex ion?

  A complex ion consists of a central metal ion surrounded by ligands.