Electronic configuration of Lanthanoids & Bohr's bury's rule

Electronic configuration of Lanthanoids;

ce (58) to lu(71) electronic configuration of lanthanoid cannot be predicted corrected by Aufbau principal.

for eg. after filled 6s orbital in barium the next electron in lanthanum should enter 4f orbital in fact it does not happen and next electron goes in 5d orbital. so electronic configuration of lanthanoid[ 57] |xe|6s^2 5d^1.

Electronic configuration of Actinoids;

electronic configuration of actinoids cannot be predict correctly by aufbau principal

for eg. After filling 7s orbital in radium(88) the next electron in actinium should 5f orbital. in fact it does not happen and next electron goes in 6d orbital .so electronic configuration of actinium[89] |Rn|7s^2 6d^1.

Bohr's bury's rule (n+l) rule:

According to this rule the energy of an orbital depends upon (n+l) value, the orbital with lower value of (n+l) will be lower energy and will filled first.

for eg.
3d 4s
n=3 n=4
l=2 l=0
n+l=5 n+l=4

since (n+l) value is less for 4s orbital is lower energy is filled earlier than 3d.

if (n+l) comes out to be same than orbital will lower value of 'n' will be lower energy and is filled first.

for eg. 3d 4p
n=3 n=4
l=2 l=1
n+l = 5 n+l= 5
since ( n+l) value comes out be same for 3d and 4p orbital but value of n is less for 3d orbital so 3d orbital of lower energy and is filled earlier than 4p.

Comments

Radial probability distribution for p and d orbital, radial wave functions

Radial probability distribution for p and d orbital Radial and Angular wave function: the radial part of wave function depends upon quantum no. n and l and gives the distribution of electron w. r. t distance .it is governed mainly exponential term e^-Zr/na°(a not) here e based on natural log. Z Atomic number r distance from nucleus n principal quantum no. or radial quantum no. a° 0.529A° for hydrogen ( Bohr radii) the exact mathematical expression for radial part of wave function for 1s or 2s and 2p orbitals. n= 1 ,l=0 s orbital R(r) =2× (z/a°) ^3/2 ×(2-zr/a°) ×e^-zr/2a° n= 2 ,l=0 2s orbital R(r) = (z/a°) ^3/2 ×(2-zr/a°) ×e^-zr/2a° n= 2 ,l=1 2p orbital R(r) = 1√3×(z/2a°) ^3/2 ×(zr/a°) ×e^-zr/2a ° the rad...

Radial probability distribution curves

Radial probhjjhajajbability distribution curves: The probability of finding the electron is given by the quantity sie^2.By radial probability us probability of finding the electron within small Radial space around the nucleus. volume of spherical shell between radius r and r+dr =4πr^2 and probability of finding the electron will be 4πr^2dr sie^2. radial probability distribution curves are obtained by plotting radial probability at various distance from the nucleus . 1.Radial probability distribution curves for S orbital n=1, l= 0. distance from nucleus here A° is called angstrom. the probability of finding of electron in a shell is maximum at distance r=r° (r not) which is 0.529 A° for H atom. diagram shows that probability plot for 2s has(two region of high probability) or (two peaks) separated by node. we conclude that no. of high probability region in S orbital = n no. of node = ( n-1)

Linear combination of atomic orbital, Molecular orbital theory, Difference between bonding & anti bonding moleculer orbital.

Linea combination of atomic orbital molecular orbital are formed by combination of atomic orbital if ꌏ(A) andꌏ(B) are the wave function of atomic orbital of two combining atomic A and B then according to Linea combination of atomic orbital, these two wave function can be added or can be substracted .that means there are two modes of interaction (symmetric and antisymmetric) We know ꌏ(s) = ꌏ(A) +ꌏ(B) ꌏ(a) = ꌏ(A)- ꌏ(B) ꌏ(s) and ꌏ(a) represent wave function of bonding and antibonding moleculer orbital. the formation of moleculer orbital ꌏ(s) and ꌏ(a) from two atomic orbital ꌏ(A) and ꌏ(B) is represented as Molecular orbital theory (MO) theory: main points of mo theory are: 1.whwn atomic orbital combine they formed molecular orbital. 2.Number of molecular orbital formed is equal to number of atomic orbital combine. 3.atomic orbital are uninuclear while molecular orbital a...

Chemistry

Search This Blog