Influence of ''direct'' and ''indirect'' pathways of dissociative chem
isorption on the form of kinetic dependences theta(MCS) and S(theta) w
as studied by the Monte Carlo method. Langmuir adsorption observed at
S-indir/S-dir less than or equal to 0.1 gradually changes to island-me
diated adsorption with an increase of the ''indirect'' adsorption cont
ribution at 0.1 less than or equal to S-indir/S-dir less than or equal
to 1.0 At S-indir/S-dir greater than or equal to 1.0 the island-media
ted adsorption dominates: large adsorption islands arise and gradually
grow.