Colorado State University

This week Adam shows us how to make an awesome glowy science experiment.

Materials Required

• clear plastic bottles
• rubbing alcohol and water mixture
• salt
• highlighter markers
• an ultraviolet (UV) light (also called a blacklight)

How to Build

Combine the salt and rubbing alcohol until it separates into alcohol on the top and salt water on the bottom. You can add more water if you want the bottom layer to be bigger. Carefully remove the back of the highlighter and squeeze the liquid into the alcohol/water mixture. Pour the entire mixture into a clear plastic bottle and hold near a UV light. Admire the pretty colors!

What’s Going On

Different highlighters dissolve in either water or alcohol. Alcohol and salt water do not mix, and alcohol is less dense so it floats on top of the water. We can’t see the ultraviolet light put out by the “blacklight”. The dye in the highlighter absorbs the UV, and re-emits the energy in colors we can see! This is called fluorescence.