Junior High School Chemical Learning -Chemical Nature

1. Concept: The nature of material in chemical changes.

2. area:

(1) Combusticity (substances with this nature are often used as energy, hydrogen, methane, etc.); burning (such substance can help combustible substances burn, such as oxygen, magnesium bands cannot be separated from oxygen)) , Combustic and burning is a pair of contradictions, opposing each other, interdependence.

(2) Oxidation (such as oxygen, chlorine, etc.), reducing (hydrogen, charcoal, magnesium, etc.), oxidation and reduction are also a pair of contradictions, closely related.

(3) acidic (such as hydrochloric acid, sulfuric acid, nitric acid are acidic), alkaline (sodium hydroxide, potassium hydroxide, calcium hydroxide, etc.), neutral (water, sodium chloride, potassium nitrate and other substances The water solution is neutral), and acidity and alkaline are relative.

(4) Metal (the ability to lose electrons, such as magnesium, iron and other metals with metal), non -metallic attributes (the ability to obtain electronics, such as oxygen, chlorine gas and other non -metals have non -metallic attributes).

(5) Stability (the ability to decompose compounds, such as carbonate is unstable, and is easy to decompose to form water and carbon dioxide).

(6) Toxicity (such as sulfur dioxide, nitric oxide, carbon monoxide is toxic), corrosive (such as sodium hydroxide solution, concentrated sulfuric acid has strong corrosiveness).

3. A substance can only discover its chemical properties in chemical changes, and the chemical properties of matter cannot be obtained in physical changes. The chemical properties of substances determine the occurrence of chemical changes. Through the chemical changes of substances, it can also reflect the chemical properties of the material.

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