--%>
Assignment Help - homework help

  Factors governing ionization energy

Factors governing ionization energy:

The ionization energy depends on the factors shown below:

(A) Size of atom or ion:

The ionization energy reduces with the rising size of atom. The bigger the size of atom, lesser is the ionization energy. It is due to the fact that electrons are closely held in smaller atoms while in large atoms, electrons are held quite loose, that is, lesser energy is needed for elimination of electrons from larger atoms than the smaller one. Therefore ionization energy is smaller for bigger atoms and higher for lower atoms.

Example:

The I.E of Be (i.e., At. No.4) is bigger than that of Li (i.e., At. No.3) since the nuclear charge of Be (I.e., Z=4) is bigger than Li (i.e., Z=3). Bigger the nuclear charge, greater would be the force of attraction among nucleus and outermost electron.

Therefore, the first I.E. of Be is more than that of Li.

(b) Magnitude of nuclear charge:

The bigger the nuclear charge of protons in the nucleus, the bigger is the ionization energy. Since of the higher nuclear charge, the electrons are bound with much force and therefore higher energy will be needed for their elimination. For occasion, magnesium has high nuclear charge (i.e., 12 protons) as compared to sodium (i.e., 11 protons). Therefore ionization energy in case of magnesium is high as compared to sodium.

Likewise the I.E. of fluorine is more than that of oxygen. It can be demonstrated as follows:

F (Z = 9; 1s2 2s2 2px2 2py2 2pz1) is containing more nuclear charge than oxygen (Z = 8; 1s2 2s2 2px2 2py1 2pz1).  In both the situations the electron has to be eliminated from the similar 2p-subshell. Since fluorine contains more nuclear charge than oxygen, this means that the nucleus of fluorine will attract the outer 2p-electrons much firmly than oxygen. Therefore, first I.E. of fluorine would be greater than that of oxygen.

(c) Effect of number of electrons in the inner shells: (Screening or shielding effect):

The attractive force applied by the nucleus on the most loosely bound electron is at least partly counterbalanced by the repulsive forces applied by the electrons existed in the inner shells. The electron to be eliminated is therefore shielded from the nucleus by the electrons in inner shell. Therefore, the electron in the valence shell experiences less attraction from nucleus. Therefore the ionisation energy will be less. This is the other reason why ionization energy reduces in moving down a group.

(d) Effect of shape of orbital:

The shape of orbital too influences the ionization potential. Since s-electrons stay closer to the nucleus than p-, d-, and f-electrons of the identical valence shell, the ionization energy reduces in the order specified below:

s > p > d > f

For illustration, the first ionization energy of aluminium is lesser than that of magnesium. The electronic configuration of magnesium is [Ne] 3s2 and that of aluminium is [Ne] 3s2 3p1. Therefore, one has to eliminate 3p-electron in case of aluminium and 3s electron in the situation of magnesium. Though it is easier to eliminate the p electron as compare to the s-electron. Therefore, the first ionization energy of aluminium is lesser than that of magnesium.

(e) Effect of arrangement of electrons:

The more stable the electronic arrangement is the greater is the ionization energy. Since the noble gases have maximum stable electronic arrangements, they exhibit maximum ionization energy.

 

Latest technology based Chemistry Online Tutoring Assistance

Tutors, at the www.tutorsglobe.com, take pledge to provide full satisfaction and assurance in Periodic Properties homework help via online tutoring. Students are getting 100% satisfaction by online tutors across the globe. Here you can get homework help for Periodic Properties, project ideas and tutorials. We provide email based Periodic Properties homework help. You can join us to ask queries 24x7 with live, experienced and qualified online tutors specialized in Periodic Properties. Through Online Tutoring, you would be able to complete your homework or assignments at your home. Tutors at the TutorsGlobe are committed to provide the best quality online tutoring assistance for Inorganic-Chemistry Homework Help and assignment help services. They use their experience, as they have solved thousands of the Chemistry assignments, which may help you to solve your complex issues of Periodic Properties. TutorsGlobe assure for the best quality compliance to your homework. Compromise with quality is not in our dictionary. If we feel that we are not able to provide the homework help as per the deadline or given instruction by the student, we refund the money of the student without any delay.