Final answer:
A small, slippery, and spherical mass is called a droplet.
Step-by-step explanation:
The small, slippery, and spherical mass described in the question is called a droplet (option c).
This term is commonly used in the context of liquids and refers to a tiny spherical mass of liquid. The shape of a droplet is determined by the intermolecular forces acting on the liquid molecules, which tend to minimize the surface area and maximize the attractive interactions.
For example, raindrops are almost spherical due to intermolecular attractive interactions between water molecules, while drops of water on a waxed (nonpolar) surface form round beads because of the weak interaction with water.