Chemical reactivity is maximum for elements from group 1 and group 17.
Chemical reactivity is maximum for elements from group 1 and group 17.
The correct option is A True
Periodic Trends and Chemical Reactivity: The atomic and ionic radii, as we know, generally decrease in a period from left to right. As a consequence, the ionization enthalpies generally increase (with some exceptions) and electron gain enthalpies becomes more negative across a period. In other words, the ionization enthalpy of the extreme left element in a period is the least and the electron gain enthalpy of the element on the extreme right is the highest negative (Note: noble gases having completely filled shells have rather positive electron gain enthalpy values). This results into high chemical reactivity at the two extremes and the lowest in the centre. Thus, the maximum chemical reactivity at the extreme left (among alkali metals) is exhibited by the loss of an electron leading to the formation of a cation and at the extreme right (among halogens) shown by the gain of an electron forming an anion. This property can be related with the reducing and oxidizing behavior of the elements.
It can also be directly related to the metallic and non-metallic character of elements. Thus, the metallic character of an element, which is highest of the extremely left decreases and the non-metallic character increases while moving from, left to right across the period.
True
Periodic Trends and Chemical Reactivity: The atomic and ionic radii, as we know, generally decrease in a period from left to right. As a consequence, the ionization enthalpies generally increase (with some exceptions) and electron gain enthalpies becomes more negative across a period. In other words, the ionization enthalpy of the extreme left element in a period is the least and the electron gain enthalpy of the element on the extreme right is the highest negative (Note: noble gases having completely filled shells have rather positive electron gain enthalpy values). This results into high chemical reactivity at the two extremes and the lowest in the centre. Thus, the maximum chemical reactivity at the extreme left (among alkali metals) is exhibited by the loss of an electron leading to the formation of a cation and at the extreme right (among halogens) shown by the gain of an electron forming an anion. This property can be related with the reducing and oxidizing behavior of the elements.
It can also be directly related to the metallic and non-metallic character of elements. Thus, the metallic character of an element, which is highest of the extremely left decreases and the non-metallic character increases while moving from, left to right across the period.
