How does bleach make things whiter?

Answered by Dr. Cathy Riddle, Chemist, Idaho National Laboratory Bleach is an oxidizing agent. This means that the bleach will react in certain ways with certain groups of chemicals. Natural stains, as well as dyes, are produced from chemical compounds called chromophores. Chromophores are generally molecules with long chains of alternating “double” and “single” bonds…

I read that astronauts are not weightless, they are just falling at the same speed as their spaceship. I don’t get it. Can you explain it?

Answered by Dr. Brian Tonks, Astronomy Professor, BYU-Idaho It is true—astronauts are not weightless. Weight, as scientists use the term, refers to the gravitational attraction of a planet (or moon) for another object. For example, when you step on a bathroom scale, it reads your weight, let’s say 100 pounds. This means that the Earth…

If molecules in colder things get denser, why does ice float?

Answered by Flint Hall, Hydrogeologist, Idaho Department of Environmental Quality Water is the most important chemical to life on earth and perhaps anywhere else in the universe. A chemical is a substance with a specific composition (or ingredients). The most basic chemicals are atoms of elements. These elements can combine to form molecules with specific…