Colloid chemistry is the study of colloids, which are mixtures where tiny particles are dispersed throughout a continuous medium. These particles, typically ranging from 1 nanometer to 1 micrometer in size, do not settle out and can remain suspended for long periods. Common examples of colloids include milk, fog, and paint. In colloid chemistry, the interactions between the dispersed particles and the medium are crucial. Factors such as surface tension, viscosity, and stability play significant roles in determining the properties and behavior of colloidal systems. Understanding these interactions helps in various applications, including food science, pharmaceuticals, and materials engineering.