Transition Metals: Variable Oxidation State, Colour and Catalysis · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

What makes a transition metal

Science · Chemistry · ages 17-18
Name ______________________   Date ____________

  1. Why does zinc not qualify as a transition metal?

    • It sits outside the d block
    • It has only one electron shell
    • Its Zn2+ ion has a full d sub-shell

  2. What makes an element a transition metal?

    • A partly filled d sub-shell in the metal or its ion
    • A full outer shell like the noble gases
    • A single oxidation state in all compounds

  3. Iron can exist as Fe2+ in FeCl2 and as Fe3+ in FeCl3.

    Circle one:   True   False

  4. Why does scandium not qualify as a transition metal?

    • Its only ion Sc3+ has an empty d sub-shell
    • It forms too many coloured compounds
    • It sits in group 1 of the table

  5. Why are copper compounds usually coloured while zinc compounds are white?

    • Copper is heavier than zinc
    • Copper has a d level gap that absorbs visible light
    • Zinc reflects all light because it is a metal

  6. What part do oxidation states play when NO catalyses ozone loss?

    • They stay fixed while the shape changes
    • Nitrogen flips +2 to +4 and back as NO is remade
    • Oxygen flips states while nitrogen watches

  7. Which pair names one heterogeneous and one homogeneous catalyst from the lesson?

    • Car catalytic converter surface with exhaust gases, and NO gas with ozone
    • Two gases reacting with no catalyst at all
    • Two solids grinding together in a mill

  8. A student says zinc compounds are white because zinc is unreactive. What is the real reason?

    • Zinc reacts too slowly to form colours
    • Its full d sub-shell leaves no gap to absorb light
    • Its compounds contain no electrons at all
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Answer key

For grown-ups. Fold this page away before handing over the rest.

What makes a transition metal W1-mt_UIVC6d7wak-s1

  1. Its Zn2+ ion has a full d sub-shell · Zn2+ holds ten d electrons with no gaps, so it fails the part-filled test.
  2. A partly filled d sub-shell in the metal or its ion · The part-filled d sub-shell is the test. Empty or full fails it.
  3. True · The d sub-shell allows several stable states. The sentence is true.
  4. Its only ion Sc3+ has an empty d sub-shell · Sc3+ has lost all its d electrons, so the sub-shell is empty, not partly filled.
  5. Copper has a d level gap that absorbs visible light · Split d levels in copper swallow part of the spectrum. Full zinc has no gap to jump.
  6. Nitrogen flips +2 to +4 and back as NO is remade · NO becomes NO2 and then NO again, so the flipping state drives the catalysis.
  7. Car catalytic converter surface with exhaust gases, and NO gas with ozone · The converter stays put while gases stream past, while NO mixes as a gas with gases.
  8. Its full d sub-shell leaves no gap to absorb light · Colour needs a d gap and a jump. Full zinc offers neither, whatever its reactivity.
Worksheet · LightMySky