ionisation enthalpy & variation with group & periods

Ionisation enthalpy(energy):

Ionisation enthalpy may ne defined as amount of energy required to remove most loosely bound electron from an isolated gaseous atom to from gaseous cation.

eg.

solid→liquid→gas→M(g) -1e^- →M(g) ^+
heat not require gas atom gaseous cation

Variation of ionisation energy in a group:

Ionisation energy decrease from top to button ina group because size of the atom increase. attraction between nucleus and valence electron decrease.

Variation of ionisation energy in a period:

Ionisation energy increase from left to right in a period because as effective nuclear charge increase .attractive between nucleus and valence electron increase so Ionisation energy is increase in period.

Successive ionisation energy:

After the removable of first electron it is possible to remove 2nd, 3rd, and even more electron .Amout of energy required to remove successive or subsequent electron are known as successive ionisation energy.

I. E(3) >I.E(2) >I.E(1)
Amount of energy required to remove 1st electron called I. E(1) and
Amount of energy required to remove 2nd electron called I. E(2) and

Amount of energy required to remove 3rd electron called I. E(3) .
It is observed that

I. E(3) > I. E(2) > I. E(1)

second ionisation energy is more than first ionisation energy. because after the removable of first electron the atom change into mono valent cation n+1 in effective nuclear charge is more. so more energy is required to remove 2 nd electron. hence I. E (2) is more than I. E(1).

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 radial wave function can be represented by plotting radial function R(r) apart distance(r)

Physical significance of sie and sie^2

Physical significance of sie and sie^2 The wave function sie has no physical significance, it simply represents amplitude of wave while square of amplitude sie^2 represent intensity of electron. i. e sie ^2 gives probability of finding the electron in space .p the space is called atomic orbital A zero value of sie^2 means probability of finding the electron is zero and high value of sie^2 means greater chances of finding the electron . the value of sie^2 lies between 0&1. if sie^2 =1 100℅ sie^2=0 0℅

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 are polynuclear. 4.The various molecular orbital are arranged in order of in increas

Chemistry

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