The valency of cerium is 4.
Cerium (Ce) is a fascinating element, identified by its atomic number 58 and classification as a lanthanide within the f-block of the periodic table. Valency refers to an element's combining power with other elements when forming chemical compounds. It indicates the number of bonds an atom can form. For cerium, its most stable and commonly observed valency is 4.
Understanding Cerium(IV)
When cerium exhibits a valency of 4, it forms compounds where it has effectively lost four electrons, resulting in a +4 oxidation state. This form is often referred to as Cerium(IV) or the ceric state. Cerium(IV) compounds are notably stable and are widely utilized across various industries due to their unique properties.
Key characteristics and applications of Cerium(IV) include:
- Strong Oxidizing Agent: Cerium(IV) compounds are powerful oxidizing agents, making them valuable in analytical chemistry, particularly in redox titrations. For instance, ceric ammonium nitrate (CAN) is a common reagent used in organic synthesis.
- Catalytic Properties: Cerium oxides, especially ceria (CeO₂), are crucial catalysts and catalyst supports. They are extensively used in automotive catalytic converters to reduce emissions, benefiting from cerium's ability to easily switch between +3 and +4 oxidation states, thereby storing and releasing oxygen.
- Polishing Agents: Cerium oxide is a highly effective abrasive for polishing glass, optics, and precision surfaces, valued for its gentle yet efficient action.
- UV Absorption: Cerium(IV) compounds can absorb ultraviolet light, finding applications in UV filters and as a component in self-cleaning ovens.
Valency Across Elements
To illustrate how valency differs among elements, consider the following examples of common valencies:
| Element | Valency |
|---|---|
| Actinium | 3 |
| Cerium | 4 |
| Cesium | 1 |
| Chlorine | 5 |
| Chromium | 6 |
This table highlights how valency is a fundamental property that dictates how elements interact and form the vast array of chemical compounds that exist.
