Question

difference between Stable electronic configuration and unstable configuration.

Answer 1

electronic configuration that have 2 or 8 electrons in its outermost she'll is called stable e.c.if it has 1 3 4 5 6 7 electrons it is called unstable e.c

Answer 2

hey friend,

stable electronic configuration:

when there are 8 electrons in the outermost shell of an element then it is said to be stable electronic configuration. exception: helium which has 2 electrons in outermost shell is also stable. {all of these are noble gases which are unreactive}

unstable electronic configuration

the elements which have less than 8 electrons in the outermost shell are said to have unstable electronic configuration. 

hope you like my answer :)