Apure substance that cannot be broken down into any other substance by chemical or physical means is a ?

A pure substance that cannot be broken down into any other substance chemical or physical means is a element.

Elements  are the elemnts have same numbers of protons or we can say that elements. It is made up of only one type of atom. example is hydrogen. In hydrogen one proton and one electron is present.

its temperature is increasing. this causes molecular vibrations to increase.