- The concept of “substance” in philosophy:
- In philosophy, “substance” is the foundation of reality, representing the essence of things, which “is” without needing anything else.
- Substance is often contrasted with “accident” or “attribute,” and it doesn’t change despite accidental variations.
- Substance in Chemistry:
- In chemistry, compounds are substances made up from at least two different elements, with a fixed composition ratio and a specific structure.
- A compound differs from a mixture, and the elements cannot be separated from the compound by physical methods.
- A chemical formula determines the number of atoms of each element in a molecule of a compound.
- The position of substance in nature and artificial objects:
- Substance is the basic component of everything around us, including both natural objects (rivers, animals, plants, mountains) and man-made objects (books, bicycles, clothes, phones).
- Examples of substances in nature include seawater (sodium chloride) and limestone mountains (calcium carbonate).
- Properties of substances:
- Substances have physical properties (solid, liquid, gas, color, boiling point, melting point, specific gravity) and chemical properties (degradability, combustibility).
- These properties can be determined through observation, using measurement tools, or experiments.
- Examples of elements and compounds:
- Elements include substances made from a single chemical element, including metallic elements and non-metallic elements.
- Compounds are substances composed of two or more chemical elements in a fixed ratio.
Through these examples, you can better understand the difference between elements and compounds, as well as the important role of chemical formulas in determining the properties of substances.