What is the lightest substance in nature?
The world of nature includes all the wonders of our luxurious planet and far beyond. It extends to who know where beyond the solar system, the milky way and the reaches of outer space. In a quest for the lightest substance, we might have to travel far afield from our home in the heavens. A substance is made of matter, either solid, liquid or gaseous. All matter is composed of atoms or molecules or ions or of even smaller fragments called subatomic particles. The weight of a substance depends upon the size of its particles and its density, which is the number of particles packed into a certain space. On earth, the densest natural metal is osmium, and an ordinary house brick of this silvery substance weighs 56 pounds. The lightest earth substances, of course, are gases that have plenty of space between their separate atoms and m01ecules of matter. And the lightest of the gaseous elements is hydrogen. The amount of hydrogen on earth is very slight. But this lightest element is abundant in
