Question -
Answer -
1. F (fluorine) exhibitsonly -ve oxidation state (- 1) in its compounds because it is the mostelectronegative element.
2. Cs (cesium) exhibitsonly +ve oxidation state (+ 1) its compounds because it is the mostelectropositive element.
3. Iodine has sevenelectrons in the valance shell as well as vacant 5d orbital to which electronsfrom 5p and 5s orbitals can be shifted. Therefore, the elements exhibits – 1oxidation state as well as variable positive oxidation states of + 1, +3, +5and +7 in its compounds.
4. Ne (neon) neitherexhibits +ve nor -ve oxidation states because it is a noble gas element withcompletely filled orbitals (Is2 2s22p6).Moreover, it has no vacant d-orbitals.