Q. Which of the following may be colourless?
A) $Fe^{3 +}$
B) $Cr^{3 +}$
C) $Cu^{2 +}$
D) $Cu^{+}$
Explanation
(d)
Cu
$3d^{10}$ $4s^{1}$
[table] ⥮ | ⥮ | ⥮ | ⥮ | ⥮ | | $\upharpoonleft$ [/table]
$Cu^{+}$
$3d^{10}$ $4s^{0}$
[table] ⥮ | ⥮ | ⥮ | ⥮ | ⥮ | | [/table]
$Cu^{+}$ is colourless due to the absence of unpaired electron
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.