Question

decrease in ionisation potential of element leads to decrease in non metallic character of elements

Answer 1

ionization means an electron remove from an isolated gaseous atom.
but we also know non metal have tendency to gain electron is higher then tendency of lose electron. hence non metal doesn't want to lose electron.but just oppsite characters in metal .metal have more tendency to lose electron.so metal easily loose electron hence ionization potential of metal is less then non metal .
so, above reason we concluded that decrease ionization potential when decrease in non metallic characters.