I need some help understanding how some ions have the same electronic arrangement as noble gasses? Like why does a Li+ ion has the same electron structure as helium or a Mg2+ ion has the same electron structure as a Na+ ion and an O2- ion?
2 Answers
A noble gas electron structure where the outmost electron shell is completely filled. Elements other than VIII A elements can achieve a completely filled outer shell by gaining or losing electrons.
Explanation:
A completely filled outer electron shell is stable because it can not gain any more electrons, it is full. Being completely full it has no desire to lose electrons thereby losing its stable structure.
Neon for example has 10 electrons. Its electron configuration is
The
Oxygen starts with an electron configuration of
This is two electrons short of the stable structure of Neon. By gaining two electrons Oxygen can achieve this stable structure so
Sodium starts with an electron configuration of
This is one more electron than the stable structure of Neon. By losing one electron Sodium can achieve Neon stable structure so
Elements electron configurations are all about achieving stability.
The most stable electron configurations are those of the noble gases.
Here's what I get.
Explanation:
The electron configuration of helium is
The electron configuration of lithium is
To form
The electron configuration of
That's the same electron configuration as for
The electron configuration of
The electron configuration of
The electron configuration of
The electron configuration of
The electron configuration of
The electron configuration of
In each case we formed the ions by adding or removing electrons and ended up with the same
