Colour, magnetism, catalytic properties
d-Block Elements (Transition Metals) · Chemistry
Study notes
CuSO₄ solution is blue but ZnSO₄ is colourless. Explain. Step 1: Cu²⁺ is d⁹ — one vacancy in d orbitals allows d–d electron transitions. Step 2: These transitions absorb orange-red light (~800 nm). Step 3: We see the complementary colour: blue. Step 4: Zn²⁺ is d¹⁰ — full, no d–d transition possible → colourless!