The atom cannot be broken by chemical methods.
An element.
an element is a substance that cannot be broken down into a simpler form by chemical means
You think probable to an atom.
because a substance cannot be decomposed into simplier substances by chemical or physical means
A substance that cannot be broken down is a pure substance
An element is a pure substance that cannot be broken down into simpler substances by chemical means.
Any substance that cannot be broken down into simpler substances is an?
If an unknown substance cannot be broken down into simpler substances it is made of one kind of atom and an element.
element
Its Elements
No. Elements cannot be broken down into simpler substances in a chemical reaction.
I think your referring to an element, the basic unit(s) that cannot be broken down without fission.