Difference Between Molecule and Mixture

分子与混合物

Difference between molecule and mixture is something we need to know when we are examining the concept of matter. Matter can be classified as pure substances and mixtures. Generally, we need both mixtures and纯物质在我们的生活中为不同的目的。咕噜咕噜叫e substances are the elements in theperiodic tableand the molecules formed by reacting two or more elements. This article describes the properties of molecules and the properties of mixtures. Also, mixtures and molecules have many differences than similarities. Here we discuss the difference between molecules and mixtures too.

What is a Molecule?

咕噜咕噜叫e substances contain only one type of化合物。Molecule is the smallest unit of a pure substance , which is responsible for itschemical properties。It has a fixed mass and a definite atomic composition. Molecules can be monoatomic (Inert gases：霓虹灯 - NE，氩 - AR，氦- 他，krypton - kr），diatomic（Oxygen– O2,氮– N2,Carbon monoxide– CO), triatomic (Water – H2O,臭氧– O3, NO2 – Nitrogen dioxide) or polyatomic (Sulfuric – H2SO4, Methane – CH4). Most of the compounds have more than one atom in their molecules. If a molecule contains only one type of element, they are called homonuclear molecules; Hydrogen (H2), Nitrogen (N2), Ozone (O3) are some examples for the homonuclear molecules. Molecules containing more than one type of elements are called heteronuclear molecules; Hydrogen chloride (HCl),ethane（C2H4），硝酸（HNO3）是异核分子的一些例子。

什么是混合物？

A pure substance contains only one type of molecule. In a mixture, there are two or more pure substances. Substances in a mixture are combined physically, but not chemically. Mostly, physical methods are used to separate compounds in a mixture. In a mixture, each substance keeps their individual properties.

混合物可以分为两组，即“homogeneous mixtures” and “heterogeneous mixtures”。均匀的混合物在整个混合物上在原子或分子水平上都是均匀的，并且在整个混合物中，异质混合物的混合物不均匀。大多数异质混合物都没有独特的组成。它因样品而异。

• Homogeneous mixtures: They are called solutions.

Examples:

Air is a gaseous solution of several gases (O2, CO2, N2, H2O, etc.)

黄铜是铜（CU）和锌（Zn）的固体溶液。

Blood

• Heterogeneous mixtures:

Sandy water, oil and water, water with ice cubes in it, salty water (salt is completely dissolved)

What is the difference between Molecule and Mixture?

•元素相互反应以制成分子，但是混合物中的化合物不会相互反应。

• Physical methods are used to separate components in a mixture, but elements in a molecule cannot be isolated using physical methods.

• Elements become more stable when they form molecules. Example: Sodium (Na) is flammable when it contacts water or it reacts very quickly when it is exposed to the air. Chlorine (Cl2) is a toxic gas. However, sodium chloride ( NaCl) is a very stable compound. It is neither flammable nor toxic.When a mixture is formed, it does not affect the stability of any substances.

•混合物的沸点低于混合物中任何单个物质的沸点。分子的沸点取决于几个因素（分子量, intermolecular weight, intramolecular weight, etc.).

• Molecules can be either homonuclear or heteronuclear depending on the types of molecules present in the molecule. Mixtures are either homogeneous or heterogeneous depending on the uniformity throughout the mixture on an atomic or molecular level.

Summary:

分子与混合物

Molecules are pure substances and they contain one or more types of chemical elements. A molecule has a definite molecular weight and a unique chemical formula. Mixtures contain more than two substances in different proportions. Those different substances in a mixture are mixed together, but they are not joined with each other. Each substance in a mixture keeps its own properties. Different substances can be easily identified in a heterogeneous mixture whereas it is difficult to identify different components in a homogeneous mixture.