The catalytic activity of transition metals is often associated with their ability to exhibit variable oxidation states. This variability in oxidation states allows them to readily undergo redox reactions, which are a common feature of many catalytic processes. Transition metals can easily donate and accept electrons in their various oxidation states, making them effective catalysts in many chemical reactions.
So, the correct option is (D): Variable oxidation states.
AB is a part of an electrical circuit (see figure). The potential difference \(V_A - V_B\), at the instant when current \(i = 2\) A and is increasing at a rate of 1 amp/second is:
A coordination compound holds a central metal atom or ion surrounded by various oppositely charged ions or neutral molecules. These molecules or ions are re-bonded to the metal atom or ion by a coordinate bond.
A coordination entity composes of a central metal atom or ion bonded to a fixed number of ions or molecules.
A molecule, ion, or group which is bonded to the metal atom or ion in a complex or coordination compound by a coordinate bond is commonly called a ligand. It may be either neutral, positively, or negatively charged.