Substances that cannot be broken down by chemical means are known as elements. An element is a pure substance that consists of only one type of atom and cannot be transformed into a simpler substance through chemical reactions.
Elements are the fundamental building blocks of matter, and they are listed in the periodic table. Each element has unique properties and cannot be decomposed into simpler substances by chemical processes. For instance, elements like hydrogen, oxygen, and gold are all examples of substances that cannot be broken down further.
In contrast, compounds are substances formed when two or more elements chemically bond together. Unlike elements, compounds can be broken down into their constituent elements through chemical reactions. For example, water (H2O) is a compound made of hydrogen and oxygen, which can be separated by chemical means.