What can you be used to identify different types of substances?

Question

My lil cuzins in 5th & shes learning about liquids & gases & stuff so it should be pretty easy.

Answer 1

Any of the multitude of physical and chemical properties can be used to identify a substance.

For example:

Let's say you had to compare sugar to table salt to baking soda.

All are white in color, but all have other properties that make them easy to identify.

Baking soda, as any elementary chemist can observe at home, bubbles with the release of carbon dioxide gas when vinegar (or any other acid) is added to it. The other two do not.

Sugar and salt will dissolve in water, but there is a difference between the two solutions: The salt solution will conduct electricity while the sugar solution will not.

You can also compare and contrast boiling and melting points, densities, texture, flexibility, maliability, etc.