Cations and anions are charged ions that lose or gain electrons in atoms or molecules, cations have positive charges, such as metal ions, hydrogen ions, etc., which have good conductivity and chemical reactivity in electrolyte solution, and can carry out electrophoresis movement in the solution, and can also participate in the reaction;Anions have a negative charge, such as chloride ions, oxygen ions, etc., and often react with cations in chemical reactions, their charges are opposite, and there is a repulsive force between them, so the presence of anions will lead to changes in the acidity and alkalinity of the solution.
1.Charge:Cions are positively charged and anions are negatively charged, which is one of their main differences.
2.How it is formed:A cation is an ion that is formed after losing an electron, such as a sodium ion is formed when a sodium atom loses an electron;Anions are ions formed after gaining electrons, such as hydroxide ions, which are formed by combining with oxygen atoms after a hydrogen atom loses an electron.
3.Atomic Radius:The larger the atomic radius, the stronger the electron loss ability, and conversely, the smaller the atomic radius, the stronger the ability to absorb electrons, for example, chloride ions have a strong ability to attract electrons because the atomic radius of the chlorine atom is larger.
4.The number of electrons in the outermost shell of an atom:A cation is an ion formed after losing an electron, so the outermost electron count of a cation is less than the outermost electron number of the atom that formed it, for example, the sodium ion loses an electron, so the outermost electron number of the sodium ion is 8-1=7;Anions are ions formed after gaining electrons, so the number of outermost electrons of an anion is more than the number of outermost electrons of the atom that formed it, for example, the hydroxide ion gains an electron, so the outermost electron number of the hydroxide ion is 1+8=9.
5.Analytical Methods:Cations are prone to change during the analysis process, and separate analysis methods are mainly used, because cations have high reactivity and need to be paid special attention during analysis to avoid side reactions. The analysis of anions is relatively simple, because the reactivity of anions is relatively low, so the analysis of anions is generally carried out by direct analysis methods and does not require special treatment.
Common cations include NA, K, NH, etc., and anions include SO, SIO, etc., and these ions have a wide range of applications in chemistry and life fields. Cationic polymerization and anion polymerization are important reactions for the synthesis of polymer compounds, and their formation and properties are closely related to ionic bonds. Ionic bonds are strong covalent bonds formed by the electrostatic attraction between cations and anions, which have an important impact on the operation of physical and living systems.
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