Answer:
Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant rocks, such as quartzite, given the right conditions.
<u>Answer:</u>
The correct answer option is a) collisions between the particles and surrounding molecules.
<u>Explanation:</u>
The collisions between the particles and surrounding molecules causes the Brownian motion of particles in a colloid.
Brownian motion is the irregular movement of the microscopic particles in a fluid which bombard into each other.
It basically is the result of the molecules of a dispersion medium colliding with the dispersed particles of the phase.