Here's why:

* Visible Light: The visible spectrum of light contains all the colors we can see, from red to violet.

* Pigments and Colors: Pigments absorb some wavelengths of light and reflect others. For example, a red object absorbs all colors except red, which it reflects.

* White Objects: White objects don't absorb any specific wavelengths. Instead, they reflect all the colors of the visible spectrum back to our eyes. This creates the sensation of white.

Examples:

* Snow: Tiny ice crystals in snow scatter all wavelengths of light equally, making it appear white.

* White Paper: Paper is made from cellulose fibers that scatter light, causing it to appear white.

* Milk: The tiny fat globules in milk scatter light, making it appear white.

Important Note: A substance can also appear white if it emits all wavelengths of light, like a white LED light bulb. However, the most common reason for a substance to appear white is because it reflects all wavelengths of visible light.