COMEDK20269 May 2026Evening ShiftChemistryd and f Block ElementsActual
Pick out the correct option Assertion(A): Mercury is not considered as a transition element Reason (R): Mercury is a liquid
Options
- AA is false but R is true
- BBoth A and R are true but R is the correct explanation of A
- CBoth A and R are true, R is not the correct explanation of A
- DA is true but R is false
Correct answer
C. Both A and R are true, R is not the correct explanation of A
Step-by-step solution
Assertion (A) is true because transition elements are defined as elements having incompletely filled d-orbitals in their ground state or in any of their common oxidation states. Mercury (Hg) has a completely filled d-orbital ( 5d¹⁰ ) in its ground state as well as in its common oxidation states. Hence, it is not considered a transition element. Reason (R) is true because mercury is indeed a liquid at room temperature. However, the physical state (being a liquid) is not the reason for mercury not being classified as