An oxide of element F has theformulaF 2 O 5 (1 mark)(a) Determine the oxidation state ofF....................................................................................................................................(b) In which group of the periodic- table iselementF

(a) The oxidation state of F in F2O5 can be determined by understanding that the oxidation state of oxygen is typically -2. Since the total charge of a compound must be zero, the sum of the oxidation states of all atoms in the compound must equal zero.

In F2O5, there are 5 oxygen atoms each with an oxidation state of -2, giving a total of -10. To balance this, the 2 atoms of F must have a total oxidation state of +10. Therefore, the oxidation state of F in F2O5 is +5 (because +10 divided by 2 equals +5).

(b) Elements with an oxidation state of +5 are found in Group 15 of the periodic table. Therefore, element F is likely to be found in Group 15.