Question

How many elements from the following are not transition element?
$Zn,Co,Cd,Hg,Au,Cu$

Answer 1

The electronic configuration of
$Zn=\left[Ar\right]3d^{10}4s^2$
$Co=\left[Ar\right]3d^{7}4s^2$
$Cd=\left[Kr\right]4d^{10}5s^2$
$Hg=\left[Xe\right]4f^{14}5d^{10}6s^2$
$Au=\left[Xe\right]4f^{14}5d^{10}6s^1$
$Cu=\left[Ar\right]3d^{10}4s^1$

Transition metals or elements are those which can form one or more ions having incompletely filled d- orbitals

$C{u}^{2+}$, $C{o}^{2+}$, $A{u}^{3+}$ these all have incompletely filled d- orbitals.Thus these are transition elements.

But $Zn$, $Cd$ and $Hg$ are not transition elements.