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Which of the following statement is wrong?A. In the lanthanide series the electrons occupy `4f`-orbitals in preference to `5d` the and `6p`-orbitals.B. Zero group was not present in the periodic table when Mendeleev presented it.C. Law of octave was presented by Newland.D. Cuprous compounds are coloured while cupric compounds are colourless. |
Answer» Correct Answer - D<br>(d) Statement (d) is wrong.<br> `Cu(Z = 29), 3rd^(10), 4s^(1)`<br> `Cu^(o+)` (cuprous) `= 3d^(10) 4s^(0)`<br> `Cu^(2+)` (cupric) `= 3d^(9) 4s^(0)` (one unpaired electron and hence is coloured). | |