Short Answer Type
Long Answer TypeWhat are successive ionisation enthalpies? Explain why the second ionisation enthalpy is higher than the first ionisation enthalpy?
Short Answer TypeWhat are the various factors due to which the ionization enthalpy of the main group elements tends to decrease down a group?
Within the main group elements, the ionization enthalpy decreases regularly as we move down the group due to the following two factors:
(i) Atomic size: As we move down the group, the atomic size of the atom regularly increases due to the addition of one new principal energy shell at each succeeding element.
(ii) Screening effect: With the addition of new shells, the number of inner electron shells, which shield the valence electron increases. In other words, shielding effect or screening effect increases.
As a result of both these factors, the force of attraction of the nucleus for the valence electrons decreases. Thus, the electron becomes less and less firmly held to the nucleus as we move down the group. Hence there is a regular decrease in the value of ionization enthalpy on moving down the group.
Why does the first ionsiation enthalpy increase as we go from left to right through a period of the periodic table?
Or
How does ionisation enthalpy vary along a period?
Why ionsiation enthalpy of N is more than that of O even though oxygen has higher nuclear charge than nitrogen?
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