Why is pure air a mixture, isn t it pure

Because the composition of the air consists of 78% nitrogen, 21% oxygen, noble gases, nitrogen dioxide, and other substances. Hence the mixture. Not pure.

Here is a distinction between purity and mixture.

A mixture, consisting of several substances (which can be thought of as a plurality of molecules) pure substances, substances composed of the same molecule or ion.

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Mixture: is a mixture of two or more substances (or composed of different substances) e.g. air, solution (hydrochloric acid, clarified lime water, iodine wine, mineral water), minerals (coal, oil, natural gas, iron ore, limestone), alloys (pig iron, steel).

Note: The substance formed by the mixture of oxygen and ozone is a mixture, as is the mixture of red phosphorus and white phosphorus.

Purities and mixtures are independent of the type of constituent elements. That is, a substance composed of one element may be pure or a mixture, and a substance composed of multiple elements may be pure or a mixture.

Pure: Composed of one substance. For example: water,

Mercury and blue alum (CuSO4·5H2O) are pure substances.

Pure air or clean air is a mixture, because the air itself is composed of a variety of gases: nitrogen (N2) accounts for about 78%, oxygen (O2) accounts for about 21%, noble gases account for about helium, neon, argon, krypton KR, xenon XE, radon RN), carbon dioxide (CO2), and other gases and impurities such as ozone (O3), nitric oxide (NO), nitrogen dioxide (NO2), water vapor (H2O), etc. --Jingrui Teacher Zhang.

A substance composed of one molecule is called a pure substance, and a mixture composed of two or more molecules is called a mixture.

Pure substance, macroscopic definition: It is composed of the same substance called pure substance, which is divided into elemental substances and compounds. Microscopic definition: A substance composed of the same kind of molecule is called a pure substance. It is characterized by a fixed composition, with fixed physical and chemical properties.

A mixture is a mixture of a variety of substances (elemental or compoundy) that are pure. The mixture does not have a chemical formula. There is no fixed composition and properties, and each element or compound retains its original properties.

In the mixture, a variety of substances contained in it do not react with each other and still maintain the original chemical properties.

The key to distinguishing whether it is a mixture or a pure substance is to see whether the substance can be written in a single chemical formula, such as water mixed with ice, the molecular formula is H2O, then it is pure; For example, hydrochloric acid is made by mixing H2O with HCl, so it is a mixture.

Matter is made up of molecules, and matter is also said to be made up of elements. Matter refers to molecules, or large aggregates of atoms. For example, oxygen is a substance composed of a large number of oxygen molecules, and an oxygen molecule is composed of two oxygen atoms, and iron is directly composed of a large number of iron atoms.

Clean air is a mixture. Because the composition of air is not a single component, but a mixture of multiple components, such as air containing oxygen, nitrogen, etc.

A mixture is a substance formed by mixing two or more substances. The mixture has no fixed chemical formula, no fixed composition and properties, and no chemical reaction occurs between the various components that make up the mixture, keeping them in their original properties. Mixtures can be physically separated from the substances.

It is not chemically synthesized.

A mixture is a mixture of two or more substances that make up the celery. The mixture does not have a chemical formula. There is no fixed composition and properties, no chemical reaction occurs between the various components that make up the mixture, they maintain their original properties.

Mixtures can be physically separated from the substances. It is not chemically synthesized.

Such as: air containing oxygen O2, nitrogen N2, noble gases, carbon dioxide CO2 and other gases and impurities; Petroleum (**), natural water, solutions, muddy water, milk, alloys, fossil fuels (coal, natural gas, oil), hydraine water, salt water containing various organic matter.

There are different methods for separating mixtures, commonly used including filtration, distillation, fractionation, extraction, recrystallization, etc.

Clean air contains nitrogen, oxygen, carbon dioxide, and other substances, which are mixtures. A mixture is a substance that is made up of a mixture of two or more substances. The mixture has no fixed chemical formula, no fixed composition and properties, and no chemical reaction occurs between the various components that make up the mixture, which retains their original properties.

Mixtures can be physically separated from the substances. The auspicious section was not composed by chemical synthesis.

By morphology

1 liquid mixture. Among them, it is subdivided: turbidity source liquid, solution, colloid.

2 Solid mixtures. For example: steel, aluminum alloys.

3 Gas mixtures. For example: air.

Press whether it is evenMixtures are divided into homogeneous mixtures and non-homogeneous mixtures. For example, air and solution are homogeneous mixtures, and slurry is inhomogeneous mixtures.