Solution:Materials are classified on the basis of appearance, solubility, and transparency.
Classification is the process of grouping various substances based on their similarities and differences. Based on the quantity of light that may flow through them, objects are divided into three kinds. There are three types of objects: opaque, transparent, and translucent. Colour, hardness, texture, and lustre all influence appearance. Materials with a lustrous look are said to have lustre. Some metals, such as iron, copper, and aluminium, frequently lose their lustre and seem dull as a result of the action of air and moisture on their surface.