18 Electron Rule Calculator

Welcome to 18 Electron Rule Calculator. Enter the data to use our basic and advanced calculator for accurate calculations. Additionally, read the formula and solved examples below to know better how it works!

Number of Metal’s d Electrons Number of Ligands’ s Electrons Number of Ligands’ p Electrons Number of Electrons involved in Metal-Ligand Bonding Total Number of Electrons (E)

Formula

Contents

1 Formula
2 Solved Examples:
3 What is 18 Electron Rule ?

The formula is:

$E = d + s + p + b$

Variables:

Variable	Meaning
$E$	stands for the total number of valence electrons in a transition metal complex.
$d$	stands for the number of electrons from the d orbitals of the metal
$s$	stands for the number of electrons from the s orbitals of the metal.
$p$	stands for the number of electrons from the p orbitals of the metal.
	stands for the number of electrons donated by the ligands (bonding electrons).

Solved Examples:

Example 1:

Given:

Electrons from d orbitals () = 6
Electrons from s orbitals () = 2
Electrons from p orbitals ( $p$ ) = 0
Electrons donated by ligands ( $b$ ) = 10

Calculation	Instructions
Step 1: E = d + s + p + b	Start with the formula.
Step 2: E = 6 + 2 + 0 + 10	Replace $d$ , $s$ , $p$ , and $b$ with the given values.
Step 3: E = 18	Add the values together to get the total number of electrons.

Answer: The total number of valence electrons is 18, indicating that the complex is likely to be stable.

Example 2:

Given:

Electrons from d orbitals ( $d$ ) = 8
Electrons from s orbitals () = 2
Electrons from p orbitals () = 0
Electrons donated by ligands ( $b$ ) = 6

Calculation	Instructions
Step 1: E = d + s + p + b	Start with the formula.
Step 2: E = 8 + 2 + 0 + 6	Replace $d$ , $s$ , $p$ , and $b$ with the given values.
Step 3: E = 16	Add the values together to get the total number of electrons.

Answer: The total number of valence electrons is 16, indicating that the complex may be less stable compared to one that adheres to the 18-electron rule

What is 18 Electron Rule ?

The 18 Electron Rule Calculator is quite helpful in inorganic chemistry that lets you know the stability of transition metal complexes. This rule says that a stable transition metal complex often has 18 valence electrons, which is similar to the noble gas configuration. It is very useful for predicting the stability of metal complexes and understanding their electronic structure.