The substance that consists of only one type of atom and is best exemplified is an element.

Here's why:

* Element: A pure substance that cannot be broken down into simpler substances by chemical means. Elements are made up of only one type of atom. Examples include:

* Gold (Au): Consists solely of gold atoms.

* Oxygen (O): Consists solely of oxygen atoms.

* Carbon (C): Consists solely of carbon atoms.

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