  With the Hamilton-Jacobi equation, we obtain the energy-momentum relation of
a charged particle as it is absorbed by the Gauss-Bonnet AdS black hole. On the
basis of the energy-momentum relation at the event horizon, we investigate the
first law, second law, and weak cosmic censorship conjecture in both the normal
phase space and extended phase space. Our results show that the first law,
second law as well as the weak cosmic censorship conjecture are valid in the
normal phase space for all the initial states are black holes. However, in the
extended phase space, the second law is violated for the extremal and
near-extremal black holes, and the weak cosmic censorship conjecture is
violable for the near-extremal black hole, though the first law is still valid.
In addition, in both the the normal and extended phase spaces, we find the
absorbed particle changes the configuration of the near-extremal black hole,
while don't change that of the extremal black hole.
