Define atomic orbital . Explain the shapes of s, p and d orbitals with the help of diagrams.

Explanation

Atomic orbital : A three dimensional space around the nucleus in an atom. Where the probability of finding an electron is maximum (j.e.) `Psi^(2)` is maximum is called an atomic orbital.
Shapes of orbitals :
a) s - orbital : Boundary surface diagram fór .s. orbital is spherical in shape, .s. - orbitals are spherically symmetric (i.e..) the probability of finding the electron at a given distance is equal in all directions.
b) p - orbitals : p - orbital consists of two sections called lobes that are either side of the plane that passes through the nucleus. The size, shape and energy of the three orbitals are identical. They differ only in the orientation. These are mutually perpendicular to each other and oriented along x,y and z axes. Each p-orbital is of dumb-bell shape.
c) d-orbitals : Five d-orbitals are designated as `d_(xy),d_(yz),d_(zx),d_(x^(2)-y)` and `d_(z^(2))`. The shapes of first four d-orbitals are similar to each other of double dumb-bell whereas that of the fifth one `d_(z^(2))` is different from others, but all five d-orbitals are equivalent in energy.