During ionisation metals lose electrons, this change can be called :

Options

A. Oxidation
B. Reduction
C. Redox
D. Displacement

Explanation

**Step-by-Step Solution:**

1. **Understanding Ionization**: When a metal undergoes ionization, it loses one or more electrons. This process is essential in forming positive ions (cations).

2. **Charge Change**: As the metal loses electrons, its charge increases. For example, if a neutral metal atom (with a charge of 0) loses one electron, it becomes positively charged (e.g., +1).

3. **Oxidation State**: The oxidation state of the metal changes from 0 (in its elemental form) to a positive value (e.g., +1). This indicates that the oxidation state is increasing.

4. **Defining Oxidation**: The process of losing electrons is defined as oxidation. Therefore, when a metal loses electrons during ionization, it is undergoing oxidation.

5. **Conclusion**: The change that occurs when metals lose electrons during ionization can be called oxidation.

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