If Z is atomic number of a metal, X is number of electrons lost during the formation of the metal ion from its atom, and Y is the number of electrons donated by the ligands, then effective atomic number (EAN) is

Options

A. EAN `=Z+X+Y`
B. EAN `=Z-X+Y`
C. EAN `=Z-X-Y`
D. EAN `=Z+X-Y`

Explanation

To find the effective atomic number (EAN) of a metal ion, we can follow these steps:

### Step 1: Identify the Variables
- Let \( Z \) be the atomic number of the metal.
- Let \( X \) be the number of electrons lost during the formation of the metal ion from its atom.
- Let \( Y \) be the number of electrons donated by the ligands.

### Step 2: Understand the Concept of EAN
The effective atomic number (EAN) is calculated by considering the number of protons in the nucleus (which is the atomic number \( Z \)), the electrons lost (which decreases the effective charge), and the electrons gained from the ligands (which increases the effective charge).

### Step 3: Write the Formula for EAN
The formula for calculating the effective atomic number (EAN) can be expressed as:
\[ \text{EAN} = Z - X + Y \]
Where:
- \( Z \) is the atomic number,
- \( X \) is the number of electrons lost,
- \( Y \) is the number of electrons donated by ligands.

### Step 4: Conclusion
Thus, the effective atomic number (EAN) of the metal ion can be represented as:
\[ \text{EAN} = Z - X + Y \]