# Ask a Teacher

### WHAT SRE SHAPES OF ATOMIC ORBITALS?

Shapes of orbitals
An orbital is the region of space around the nucleus where there is a fine probability of finding electrons .The plot of  angular wave functions (probability functions ) give us the shapes of the orbitals.

Shape of s-orbitals
For s-orbitals ,when l=0,the value of m is '0' which means there is one possible orientation and the probability of  finding an electron is the same in all directions at a given distance from the nucleus .For this reason it should be spherical in shape .Hence all orbitals are non directional and spherically symmetrical about the nucleus .The size of an s-orbital depends upon value of the principal quantum number' n'.Greater the value of 'n' larger is the size of the orbital.

In 2s orbital there is a nodal position where the probability of finding electron is zero .The number of nodal surfaces in 's' orbital of any energy level is equal to (n-l) ,where 'n' is the principal quantum number

Shape of p- orbitals
'p' orbitals have dumbbell shape and have directional character.The probability of finding electron' is equal in both the lobes.Two lobes of each orbital are separated by a nodal plane .p'- orbitals can have three possible orientations .That is for a p-sub shell l=1 there are three values of 'm' namely -1,0,+1 .These three p-orbitals are in degenerate state but differ in their orientations .Each p-orbitals consists of two lobes symmetrical about a particular axis and are denoted as 2px,2py and 2pz .

shape of d-orbitals
For d-sub shell,l=2 there are five possible values of 'm' namely -2,-1,0,1,2. That means it can have five orientations .These are represented by dxy,dyz,dzx,dx2-y2 and dz2 . The dxy,dxz,dyz , have same shape and they lie in xy.xz,yz respectively .

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