Final answer:
Elements and compounds are the primary substances that compose all matter. Elements are indivisible through chemical means, while compounds consist of two or more elements in fixed proportions and require chemical methods to be decomposed.
Step-by-step explanation:
The primary substances, of which all other things are composed, are either elements or compounds. Elements are the simplest pure substances and cannot be broken into simpler substances through chemical means. Examples include hydrogen, oxygen, and carbon, which are foundational to the organization of all matter, including living organisms. Compounds, on the other hand, are composed of two or more elements in fixed proportions and can only be separated into simpler substances by chemical methods. Water, for instance, is a compound made of hydrogen and oxygen.
Elements and compounds form the essential building blocks of the natural world, shaping everything from inanimate objects to living beings. Molecules, which are combinations of two or more atoms, further contribute to the complexity of matter, encompassing vital biological molecules like nucleic acids, proteins, carbohydrates, and lipids. These molecules are crucial for the structure and function of living organisms, following the laws of physics and chemistry in their formation and interactions.