The definition of chemical salt in junior high school is as follows:

Salt chemical formula NaCl.

salt refers to sea salt, well salt, mineral salt, lake salt, earth salt and so on from different sources. Their main component is sodium chloride, and the state stipulates that the sodium chloride content of well salt and mineral salt shall not be less than 95%. NaCl, the main component of salt, ionic compound. Pure sodium chloride crystal is colorless and transparent cubic crystal. Due to the existence of impurities, sodium chloride is generally white cubic crystal or fine crystal powder.

expansion:

1. salt; Main components; Sodium chloride, chemical formula NaCi.

2, carbon dioxide solid; Chemical formula COg, commonly known as dry ice.

3. Calcium oxide: chemical formula Ca, commonly known as quicklime.

4, calcium hydroxide; Chemical formula Ca(OH)2, commonly known as hydrated lime and slaked lime calcium hydroxide solution: commonly known as limewater, with main component ca (oh) z.

5. Methane: chemical formula CH, commonly known as the main component of natural gas, gas and biogas.

6. ethanol: commonly known as alcohol.

7. Mercury: chemical formula Hg is commonly known as mercury.

8. hydrogen peroxide: chemical formula 1., commonly known as hydrogen peroxide.

9, copper sulfate crystal; -Commonly known as choleric alum and blue alum.

1. Sodium hydroxide: chemical formula NaOH, commonly known as caustic soda, caustic soda and caustic soda.

11. Main components of marble and limestone; CaC。

12. Hydrochloric acid (HC1): hydrochloric acid (solution obtained by dissolving hydrogen chloride gas in water), scientific name: hydrochloric acid.