Profile
Settings
Refer your friends
Sign out
INTRODUCTION
There are four kinds of orbitals, marked as s, p, d and f each with a definite shape. From the four, s and p orbitals are examined due to these orbitals being the most usual in organic chemistry. An s-orbital is spherical with the nucleus at its middle, a p-orbital is dumbbell-shaped and d orbitals are cloverleaf shape.The fifth d orbital is shaped like an elongated dumbbell with a bun around its centre. The orbitals in an atom are arranged into different sheet or electron shells.
S- ORBITAL
● The form of the s orbital is spherical with the nucleus in the middle.
● The s shaped orbital is related to a sphere with a nucleus at its middle. In the2-D, it can be viewed as a circle.
● Accordingly, s orbitals can be said to be spherically shaped.
● Because of their shape, they have the chance of finding an electron at equal distances from the nucleus.
● The size of the s orbital grows with rise in the value of principal quantum number (n). Therefore, 4s > 3s > 2s > 1s.
P-ORBITAL
● All p orbitals carry two sections called lobes that lie on either side of the plane which passes through the nucleus of the atom.
● The three p orbitals are similar in shape, size and energy. But, they differ in their orientation of lobes.
● Since the lobes lie across one out of the three axes, namely, x, y and z, the three orbitals are chosen as 2px, 2py and 2pz. It can be said that there are 3 p orbitals with collective perpendicular axes.
● Like in s orbitals, the energy and size of p orbitals also rises with the rise in quantum number i.e. 4p > 3p >2p.
D- ORBITAL
● The magnetic orbital quantum number for d orbitals is expressed as (-2, -1, 0, 1, 2). Therefore, there are five d orbitals.
● The d orbitals are given the position as dxy, dyz, dxz, dx2-y2 and dz2.
● The structure of the first four d orbitals are similar to one another while being distinct from the dz2 orbital.
● The energy of all five d orbitals is similar or identical.
F- ORBITAL
● The f orbitals have correlated magnetic quantum numbers m1 (-3, -2, -1, 0, 1, 2 3).
● There secondary quantum number I = 3.
● They hide deeply below the valence shell for the elements that are even behind cerium therefore; they are not engaged in the ground state until the element cerium.
● The f orbitals are given the position and fz3.
● Each f orbital has a multi-lobed and complex shape with numerous nodal points
ELECTRON SPIN
Among the three characteristic properties of the electrons; the others are mass and charge of the electron. The electron spin is explained as the spinning of the electron around its axis.
It is expressed as: IISII = √s(s+1)h
Where,
● s is equivalent to an estimated spin vector
● The spin vector is expressed as s
● The spin quantum number is related with the spin angular momentum and h is Planck’s constant.
The spin quantum number can determined as : S=n/2
● Any positive integer can be denoted as n.
● The allowed values of the spins are 0, 1/2, 1, 3/2, 2, etc.
● The constant angular momentum of an electron is denoted by quantum number ½.
The total angular momentum s is expressed by :
s=√n(n+a)h
s=√0.5(0.5 +1)h
s=√3/4h¯
Where,
The reduced planck’s constant is h¯
Therefore h-= h/2𝛑.
DIRECTION OF SPIN
The electron can spin in two direction
● Spin up
● Spin down
The spin down and spin up direction are communicated to the spinning in the +z or –z direction. These spins are the molecules that have spins equal to 1/2, i.e. for electrons.
In quantum theory, the electron is thought to be a little magnetic bar, and its spin points to the north pole of the little bar. If two approaching electrons have the same spin direction the magnetic field developed by them builds up each other and thus a strong magnetic field is achieved. If the approaching electrons have an opposite spin direction, the magnetic field developed by them calls off each other and no magnetic field is formed.
CONCLUSION
In atoms or ions with a single electron, all orbitals with the same value of n have the same energy , and the energies of the principal shells rises smoothly as n rises . An atom or ion with the electron in the lowest-energy orbital is called to be in its ground state, while an atom or ion in which one or more electrons occupy higher-energy orbitals is called to be in an excited state. The Spins play a notable role in quantum mechanisms in determining the characteristics of elementary units like electrons. The direction of spin of the particle controls several things like the spin quantum number, angular momentum, the degree of freedom, etc.
