How can you differentiate an element from a compound?
Jerome de Leon
The smallest possible piece of an element is an atom. The smallest possible piece of a
compound is a molecule which, in turn, is composed of any number of atoms. There are only
92 different atoms (therefore, 92 elements) that exist in nature. An unlimited number of
molecules (ie. compounds) can be formed from those 92 atomic building blocks.
Elements are recognized by the inability to break them down any further by chemical or
physical means into simpler components. Water, for example, is a compound made up of
molecules. Each of those molecules contains 2 hydrogen and 1 oxygen atom. An electric
current can break down the H2O water molecule and produced hydrogen and oxygen gas. There
is no further chemical or physical way to break down hydrogen or oxygen, since they are composed of atoms.
Atoms can only be broken into simpler atoms by nuclear techniques that involve splitting atomic nuclei. Hydrogen, with the simplest possible nucleus, cannot be split into any
simple atoms but oxygen nuclei could be.
Paul Walorski, B.A., Part-time Physics Instructor
'One thing I have learned in a long life: that all our science, measured against reality, is primitive and childlike - and yet it is the most precious thing we have.'