Discuss the general characteristic of group 17 elements with reference to (i) Oxidation State (ii) ionization enthalpy and (iii) electron gain enthalpy?
Answers
(i) Group 17 elements show an odd oxidation states such as -1, +1, +3, +5, and +7 as they have 7 electrons in their outermost shell. But down the group, elements have less importance of the higher oxidation states.
(ii) Since these elements have high electronegativity which means they bind electron more tightly. Therefore, it requires more energy to isolate an electron. But down the group ionization enthalpy decrease as size increases.
(iii) These elements have extreme negative electron gain enthalpy. However, fluorine has less negative electron gain enthalpy than chlorine due to the size of fluorine. Otherwise down the group, elements have less negative electron gain enthalpy. The reason of high negative electron gain enthalpy of group 17 elements is they need only one electron to get a stable configuration.