Answer
The downward impulse on the lizard due to gravity is $~~0.529~kg~m/s$
Work Step by Step
We can find the downward impulse on the lizard due to gravity:
$J = F~t$
$J = mg~t$
$J = (0.090~kg)(9.8~m/s^2)(0.600~s)$
$J = 0.529~kg~m/s$
The downward impulse on the lizard due to gravity is $~~0.529~kg~m/s$