SHAPES OF S AND P ORBITALS, Each orbital has its own three dimensional shape, subshell have only one s orbital ,

 

SHAPES OF S AND P ORBITALS:

 

            Each orbital has its own three dimensional shape. S subshell have only one s  orbital which is spherical symmetrical. Actually there is no exact boundary for an orbital but shape of an orbital describes the probability of finding the electrons. Orbital is like charged cloud present around the nucleus.

Nucleus

           

S orbital which is

spherical symmetrical .

 

P subshell have three p orbitals, px, py and pz with lobes along x, y and z axis, The shape of p orbital is describe as dumb-belt shape which have two areas around the nucleus where probability if finding the electrons is maximum.

Similarly three are five different degenerate d orbits are present like day, dyz, daz, dx²-y² and dz² and seven degenerated of orbitals like fxyz, fz(y²-x²), fy(z²-x²), z(x²-y²),  fx³, dy³.

 

ELECTRONIC CONFIGURATIONS:

 

            Arrangement of electrons of an element in different shells, subshell and orbitals is called electronic configuration. This arrangement of electrons in an atom is called ground state configuration whereas in case of its ion it is called excited state configuration. For example, electronic configuration of Hydrogen atomic is represented like this;

 

                                                Number of electrons in the .

subshell or orbital   

 

Principal

Quantum                               

Number                                  Subshell or orbital

 

 

            There are different rules which are used to determine the electronic configuration of an element.

 

 AUF BAU PRINCIPLE:

 

            The principle state that in the electronic configuration of an element the lowest energy levels are filled first in order to give lowest possible energy state to the atom because lowest energy state configuration is the stable energy state. The order to filling the orbitals is given below:

 

            15, 25, 2p, 35, 3p, 45, 3d, 4p, 5s

 

            According to this order energy of 43 is less than 3d orbital hence it is filled first. This order is derived from (n+l) values of different orbitals where n stands for principal quantum number i.e. no of shell and l stands for azimuthal quantum number which describe shape of an orbital. For example the value of l for different orbitals is given below:

ORBITAL	VALUE FOR “L”
s	0
p	1
d	2
f	3

            Similarly table for (n+l) value of different orbitals in increasing order is given below:

ORBITAL	(N+L) VALUE
15	(1+0 = 1
25	(2+0) = 2
2p	(2+1) = 3
35	(3+0) = 3
3p	(3+1) = 4
4s	(4+0) = 4
3d	(3+2) = 5
4p	(4+1) =  5
5s	(5+0) = 5
4d	(4+2) = 6
5p	(5+1) = 6
6s	(6+0) = 6
4f	(4+3) = 7
5d	(5+2) = 7
6p	(6+1) = 7
7s	(7+0) = 7
5f	(5+3) = 8
6d	(6+2) = 8
7p	(7+1) = 8
6f	(6+3) = 8
7d	(7+2) = 9