Electronic Configurations Of Elements And The Periodic Table

Step 1: Understand the atomic number
Gadolinium (Gd) has an atomic number of $Z%20%3D%2064$ . This means it has 64 electrons in the neutral state
Step 2: Start with the nearest noble gas
The noble gas preceding Gd is Xenon (Xe), which has 54 electrons. So, we begin with: $%5Ctext%7B%5BXe%5D%7D%20%3D%20%5Ctext%7B1s%7D%5E2%20%5C%2C%20%5Ctext%7B2s%7D%5E2%20%5C%2C%20%5Ctext%7B2p%7D%5E6%20%5C%2C%20%5Ctext%7B3s%7D%5E2%20%5C%2C%20%5Ctext%7B3p%7D%5E6%20%5C%2C%20%5Ctext%7B4s%7D%5E2%20%5C%2C%20%5Ctext%7B3d%7D%5E%7B10%7D%20%5C%2C%20%5Ctext%7B4p%7D%5E6%20%5C%2C%20%5Ctext%7B5s%7D%5E2%20%5C%2C%20%5Ctext%7B4d%7D%5E%7B10%7D%20%5C%2C%20%5Ctext%7B5p%7D%5E6$ Step 3: Add remaining electrons after [Xe]
We need to place $64%20-%2054%20%3D%2010$ more electrons. These go into:

$6s$ orbital → 2 electrons → $6s%5E2$
$4f$ orbital → 7 electrons → $4f%5E7$
$5d$ orbital → 1 electron → $5d%5E1$

Step 4: Write the complete configuration
$%5Cboxed%7B%5Ctext%7B%5BXe%5D%7D%20%5C%2C%204f%5E7%20%5C%2C%205d%5E1%20%5C%2C%206s%5E2%7D$ This is the most stable configuration for Gd because the $4f%5E7$ is a half-filled subshell, which adds extra stability.

Electronic Configurations Of Elements And The Periodic Table

High-Yield Trend

Chapter Questions
1 MCQs

Official Solution

Electronic Configurations Of Elements And The Periodic Table

High-Yield Trend

Chapter Questions 1 MCQs

Official Solution

Chapter Questions
1 MCQs