what are all substances made of?

All substances are fundamentally made of atoms, which are the smallest units of elements. Elements are pure substances consisting of only one type of atom, while compounds are substances made of two or more different elements chemically bonded together. Every substance, whether it is an element or a compound, is composed of atoms and molecules that determine its chemical and physical properties. These atoms come from one or more of the 118 known elements, which include natural and synthetic ones. Mixtures are combinations of substances but are not chemically bonded, unlike compounds. Therefore, all substances are made of atoms of elements, either alone or bonded as compounds.