What are the limitations to categorizing substances in only 3 categories?

Classification helps us categorize different substances based on a set of characteristics. Define the most common characteristics of a solid and a liquid along with examples that fall under each category.What are the limitations to categorizing substances in only 3 categories? How is it useful?Provide at least two example substances found outside these 3 categories and explain why they are difficult to place in either the liquid, solid, or gas category.