For 10 points, name this process, which involves the motion of a substance down a concentration gradient.
Dynkin's formula describes the Ito type of this process, while another type of this process occurs in plasmas over a magnetic field and is named for Bohm. The namesake differential equation describing this process reduces to the heat equation when its coefficient is zero, and another law governing it relates flux to the gradient of the concentration field. In addition to being described by Fick's laws, a special case of this process occurs with water across a semi-permeable membrane and is known as osmosis. For 10 points, name this process, which involves the motion of a substance down a concentration gradient.
Dynkin's formula describes the Ito type of this process, while another type of this process occurs in plasmas over a magnetic field and is named for Bohm.
diffusion