Skip to main content

Factors determining size & important question answer

Factors determining size: 

1 Number of shell:  more are the no.  of shells bigger is the size of atomic.

2 Number of protons:  if no.  of shells are same, more are the no.  of protons, smaller in size of atom.

3 Number of electron:  if the no.  of shells and no.  of protons are same, more are the no.  of electron bigger is the size of atom.



Question & Answer

Question 1

Radii of action is smaller than corresponding atom?

ans:

 cation is formed by loss of electron. magnitude of nuclear charge remain same .but no. of electron is decrease as a result effective nuclear charge increase so electron are more attracted by nucleus. this cause decrease in size hence cations are smaller than corresponding atom

for eg.

 Na^+1<Na        Al^+1<Al   etc



Question  2

Radii of anion is bigger than corresponding atom?

ans:

anion is formed by gain of electron. magnitude of nuclear charge remains same but no.  of  electron is increase as  a result of effective nuclear charge decreases  so expansion of electron take place. this cause increase in size .
hence anion is bigger than  corresponding atom

Comments

Popular posts from this blog

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