Is there a taxonomic syllabus for chemistry junior 3 ?

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Classification of substances

(1) Mixtures and purities

Mixture: There are two or more substances in the composition. Common mixtures are: air, seawater, tap water, soil, coal, oil, natural gas, detonation gas and various solutions.

Pure: There is only one substance in the composition.

Macroscopically there is one component, microscopically there is only one molecule;

Pure substances have a fixed composition and unique chemical properties, which can be expressed by chemical formulas;

Pure substances can be made up of one element (elemental) or multiple elements (compounds).

(2) Elemental substances and compounds

Elemental: A pure substance composed of only one element. It can be divided into metal element, non-metallic element and rare gas.

Compound: A pure substance composed of two or more elements.

(3) Oxides, acids, bases and salts

Oxide: A compound composed of two elements, one of which is the element oxygen.

Oxides can be divided into metal oxides and non-metal oxides; It can also be divided into acidic oxides, basic oxides and amphoteric oxides;

Acid: A compound in which all cations ionized in solution are hydrogen ions. Acids can be divided into strong acids and weak acids; monobasic and polyacids; Oxygenated acids and anaerobic acids, etc.

Base: The cations ionized in solution are all compounds of hydroxide ions. Bases can be divided into soluble and insoluble bases.

Salt: A compound that ionizes metal cations and acid anions during ionization. Salts can be divided into normal salts, acid salts, and basic salts.

What is a substance

Matter is the physical objects and fields that make up all objects in the universe. For example, air and water, food and cotton, coal and oil, steel and copper, aluminum, and various synthetic fibers, plastics, etc., are all substances. All existence in the world is matter.

The human body itself is also a substance. In addition to physical objects, light, electromagnetic fields, etc., are also substances, and they are substances that appear in the form of fields. There are many types and forms of matter, and the properties of matter are varied.

Substances in the gaseous state, substances in the liquid state, or substances in the solid state; elemental substances, compounds, or mixtures; metals and non-metals; minerals and alloys; inorganic and organic; naturally occurring substances and synthetic substances; Inanimate matter and living matter as well as solid matter and field matter, etc. Although there are many types of matter, they have their own characteristics, that is, they can be observed or predicted by theories, and they all have mass and energy. Having different chemical formulas is different substances, and having the same chemical formula but having different structures is also different substances.

Back to the equation, the reaction phenomenon. That's it.

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