MCQ Detailed View

Transition metals are elements found in the d-block of the periodic table. They are known for their partially filled d-orbitals, which give them unique chemical and physical properties. One important property is their ability to form coordination complexes with ligands, due to the availability of vacant d-orbitals. This makes the statement “they form complexes” correct. Another common property is variable oxidation states. Because of similar energy levels of (n-1)d and ns orbitals, transition metals can lose different numbers of electrons, leading to multiple valencies. This is why compounds of transition metals often exist in more than one oxidation state.

Transition metals also form coloured ions. The colour arises from electronic transitions between d-orbitals that are split in an electric field of ligands. This property is widely used in qualitative analysis and spectroscopy.

The false statement is that “all transition metal compounds are paramagnetic.” While many transition metal compounds are indeed paramagnetic due to the presence of unpaired electrons, not all of them show this behavior. For example, zinc (Zn²⁺), cadmium (Cd²⁺), and mercury (Hg²⁺) ions have fully filled d-orbitals with no unpaired electrons, making their compounds diamagnetic. Similarly, some complexes such as [Fe(CN)₆]⁴⁻ can be diamagnetic because of strong ligand fields that pair up electrons.

Therefore, paramagnetism depends on the electronic configuration and ligand field environment. While paramagnetism is common, it cannot be generalized to all transition metal compounds. This makes the statement “all transition metal compounds are paramagnetic” false.