* It is a pure substance: Lithium metal consists of only one type of atom, namely lithium atoms. It cannot be broken down into simpler substances by ordinary chemical means.
* It cannot be created or destroyed in a chemical reaction: Lithium atoms are fundamental building blocks of matter. Chemical reactions only rearrange atoms, they don't create or destroy them.
* It has unique and consistent properties: Lithium has a specific atomic number (3), meaning it has 3 protons in its nucleus. This number determines its chemical behavior and other properties like its melting point, density, and reactivity.
Therefore, lithium metal fits the definition of an element: a pure substance that cannot be broken down into simpler substances by chemical means and has unique, consistent properties.
