1.Shapes of s-orbitals:
For s-orbital, when l =0,m has only value i.e.,0.Therefore,there is only one possible orientation.The only shape having one orientation.The only shape having one orientation is a sphere. Hence all s-orbitals are non-directional and spherically symmetrical about the nucleus.
The size of the s-orbital increases as the principal quantum number (n) increases. Therefore,the size of 2s-orbital is larger than 1s-orbital.The s-orbitals of higher energy levels are also non-directional and spherically symmetrical,2s-orbital differs in the respect that it is bigger in size and it contains a nodal surface.Nodal surface is a spherical shell within 2s-orbital where the probability of finding an electron is zero.However,there is no node in case of 1s-orbital.For 2s-orbital,there is one node and 3s-orbital has two such nodes.In general, the number of nodes in any ns orbital is given as (n-1).2.Shapes of p-orbitals:
For p-orbitals,when l=1,m has three values i.e.,m-1,0,+1.Hence there are three possible orientation. Therefore,p-orbitals are of three types.
These are represented as px,py and pz depending upon whether the electron density is maximum along the x,y and z axis respectively.These three orbitals have same energy and are called degenerated orbitals.
A p-orbitals is dumb-bell shaped region of space,have two lobes,symmetrical about a particular axis.The probability of finding the electron is same in each lobe.The two lobes of each p-orbitals are separated by a nodal plane.Thus,unlike s-orbitals these have directional character and hence are helpful in determining the shape of molecules.
Difference between orbit and orbital:
Orbit:
1. An orbit is the well-defined circular path around the nucleus in which the electron revolves it.
2. It represents the planar motion of an electron.
3. All orbits are circular.
4. Orbits donot have any directional character.
5. The maximum number of electrons which can be accomodated in an orbit is 2n2 (n=no.of the orbit.)
6.The concept of orbit is not in accordance with heisenberg's uncertainty principal.
Orbital:
1. An orbital represents the a region in space around the nucleus where the probability of finding an electron is the maximum.(90-45%).
2. It represents the three-dimensional motion of an electron.
3. Orbitals have different shapes e.g.,s- orbital is spherical whereas p-orbital is dumb-bell shaped.
4. With the exception of s-orbitals,all other have directional character.
5. An orbital cannot accommodate at the most 2 electrons.
6. It is in accordance with heisenberg's uncertainty principle.