Which of the following is/are not considered as transition elements?

Ag, Mo, Zn, Hg, W

Hg and Zn

The correct answer is Option (3) → Hg and Zn

A transition element must have a partially filled d-subshell in its atom or in one of its common oxidation states.

• Ag: forms $Ag^{2+}$ ($d^9$) $\rightarrow$ partially filled $\rightarrow$ transition element.
• Mo: has partially filled d-subshell $\rightarrow$ transition element.
• W: partially filled d-subshell $\rightarrow$ transition element.
• Zn: $Zn^{2+}$ is $3d^{10}$ (completely filled) $\rightarrow$ not a transition element.
• Hg: $Hg^{2+}$ is $5d^{10}$ (completely filled) $\rightarrow$ not a transition element.

Therefore, the elements not considered transition elements are Hg and Zn.