Explain why the electronic configuration of cu is 3d104s1 and not 3d94s2
Answers
Answer:
Some elements do not follow the Aufbau principle, there are some alternate ways that electrons can arrange themselves that give these elements better stability.
Explanation:
Using the Aufbau principle, you would write the following electron configurations
Cr = [Ar]
4s2
3d4
Cu = [Ar]
4s2
3d9
The actual electron configurations are:
Cr = [Ar]
4s1
3d5
Cu = [Ar]
4s1
3d10
To understand why this occurs, it is important to realize that...
1. Completely filled sublevels are more stable than partially filled sublevels.
2. A sublevel which is exactly half filled is more stable than a partially filled sublevel which is not half full.
3. Electrons are lazy and will do whatever places them in the lowest energy state = which is the most stable state