Raymond Southgate, age 10, of Peterborough, Ont., Canada, for his question:

 Where do we find krypton?

Krypton gas is one of the rarest Elements in the world, and not until 1898 did scientists discover that tiny traces of it are in the air. The air, of course, is made from  of  atoms and molecules. Most of these particles are either nitrogen or oxygen, but one air particle in every million or so is a particle of krypton gas. We take it into our lungs when we breathe, but we never know it, for krypton has no smell or flavor and does us no harm at all.

A little krypton sometimes escapes from deep within the Earth's crust. It may come bubbling up with the steamy water from a hot spring. Our chemists are able to gather quantities of krypton gas, and this is used to fill certain neon type light tubes.