An unknown substance is made only of identical atoms that cannot be broken down. this substance is a

Element

Explanation:

Element is a pure substance which is composed of identical atoms. It can not be decomposed into simpler constituents using chemical reactions.Example: Silver

Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: carbon dioxide

Thus an unknown substance is made only of identical atoms that cannot be broken down is an element.

answer

the ions in solute supperate from eachouthere

the solar system used to have much dust particles option no d