The Electron configuration

-Energy Level is a specific amount of energy which an electron in an atom can possess
- n is the # of energy level
-the energy different between 2 particular energy level is called quantum of energy
-Orbit is the actual region of space occupied by an electron in a particular energy level

   - n=1:only the s-type is possible
   - n=2:the s and p types are possible
   - n=3:the s p and d types are possible
   - n=4: the s p d f types are possible
-----------------------------------
   - s type sub shell consists of 1 s-orbital
   - p type sub shell consists of 3 p-orbital
   - d type sub shell consists of 5 d-orbital
   - f type sub shell consists of 7 f-orbital
-2 Electron can be placed in each orbit

-a shell is the set of all orbitals having the same N- value
 E.g the third shell consists of the 3s 3p 3d orbitals
-a subshell is a set of orbitals of the same type

- An electron configuration is a description of which orbitals in an stom electron configuration

E.g Ne(1s2 2s2 2p6)
=---------------------------------------------
Core Notation
-the set of electrons belonging to a given atom can be divided into 2 subsets: the core electrons and th outer electrons

-CORE: the set of electrons with the configuration  of the nearest noble gas having an atomic number Less than that of the atom being considered

E.g Al(1s2 2s2 2p6 3s2 3p1)------>Al([Ne] 3s2 3p1 )
        CORE       OUTER
EXCEPTION:
Cr([Ar]4s2 3d4)---->Cr([Ar]4s1 3d5) --to make 2 half filled sub shells
Cu([Ar]4s2 3d9)---->Cr([Ar]4s1 3d10)--to make a hall filled sub shell and  a filled sub shell
-----------------------------------------------------