Answer
fluorine : molecular element
$N_2O$ : molecular compound
silver : atomic element
$K_2O$ : ionic compound
$Fe_2O_3$ : ionic compound
Work Step by Step
fluorine : molecular element - occurs as the diatomic molecule $F_2$
$N_2O$ : molecular compound - composed of two non-metals
silver : atomic element - occurs as monoatomic element in nature
$K_2O$ : ionic compound - composed of a metal and a non-metal
$Fe_2O_3$ : ionic compound - composed of a metal and a non-metal