Formula unit

百度岛上前两天有专门的文章介绍过自然资源部，这是一个对自然资源开发利用和保护进行监管，建立空间规划体系并监督实施，履行全民所有各类自然资源资产所有者职责的全新机构。

In chemistry, a formula unit is the smallest unit of a non-molecular substance, such as an ionic compound, covalent network solid, or metal.^[1]^[2] It can also refer to the chemical formula for that unit. Those structures do not consist of discrete molecules, and so for them, the term formula unit is used. In contrast, the terms molecule or molecular formula are applied to molecules.^[3] The formula unit is used as an independent entity for stoichiometric calculations.^[4]^[5] Examples of formula units, include ionic compounds such as NaCl and K₂O and covalent networks such as SiO₂ and C (as diamond or graphite).^[6]

In most cases the formula representing a formula unit will also be an empirical formula, such as calcium carbonate (CaCO₃) or sodium chloride (NaCl), but it is not always the case. For example, the ionic compounds potassium persulfate (K₂S₂O₈), mercury(I) nitrate Hg₂(NO₃)₂, and sodium peroxide Na₂O₂, have empirical formulas of KSO₄, HgNO₃, and NaO, respectively, being presented in the simplest whole number ratios.^[7]

In mineralogy, as minerals are almost exclusively either ionic or network solids, the formula unit is used. The number of formula units (Z) and the dimensions of the crystallographic axes are used in defining the unit cell.^[8]

References

^ Peter Atkins, Julio de Paula, Ronald Friedman, Physical Chemistry: Quanta, Matter, and Change, 2nd Edition
^ "Does the term Formula Unit apply to giant covalent networks composed of one type of atom, like Diamond or Graphene which have formula C?".
^ "Chapter 4 – Covalent Bonds and Molecular Compounds". wou.edu. Retrieved 2025-08-05.
^ "Formula Units vs Empirical Formula - CHEMISTRY COMMUNITY". lavelle.chem.ucla.edu. Retrieved 2025-08-05.
^ "2.2: Chemical Formulas". Chemistry LibreTexts. 2025-08-05. Retrieved 2025-08-05.
^ Steven S. Zumdahl; Susan A. Zumdahl (2000), Chemistry (5 ed.), Houghton Mifflin, pp. 470-6, ISBN 0-618-03591-5
^ "Is Formula Unit usually an empirical formula but not always? - Chemical Forums". chemicalforums.com. Retrieved 2025-08-05.
^ Smyth, Joseph R. and Tamsin C. McCormick, 1995, Crystallographic Data for Minerals, American Geophysical Union

This chemistry-related article is a stub. You can help Wikipedia by expanding it.

[1] Peter Atkins, Julio de Paula, Ronald Friedman, Physical Chemistry: Quanta, Matter, and Change, 2nd Edition

[2] "Does the term Formula Unit apply to giant covalent networks composed of one type of atom, like Diamond or Graphene which have formula C?".

[3] "Chapter 4 – Covalent Bonds and Molecular Compounds". wou.edu. Retrieved 2025-08-05.

[4] "Formula Units vs Empirical Formula - CHEMISTRY COMMUNITY". lavelle.chem.ucla.edu. Retrieved 2025-08-05.

[5] "2.2: Chemical Formulas". Chemistry LibreTexts. 2025-08-05. Retrieved 2025-08-05.

[Zumdahl-6] Steven S. Zumdahl; Susan A. Zumdahl (2000), Chemistry (5 ed.), Houghton Mifflin, pp. 470-6, ISBN 0-618-03591-5

[7] "Is Formula Unit usually an empirical formula but not always? - Chemical Forums". chemicalforums.com. Retrieved 2025-08-05.

[8] Smyth, Joseph R. and Tamsin C. McCormick, 1995, Crystallographic Data for Minerals, American Geophysical Union

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

v t e Mole concepts
Constants	Avogadro constant Boltzmann constant Gas constant Faraday constant Molar mass constant
Physical quantities	Mass concentration Molar concentration Molality Mass Volume Density Mole fraction Mass fraction Amount of substance Molar mass Atomic mass Particle number Pressure Thermodynamic temperature Molar volume Specific volume
Laws	Charles's law Boyle's law Gay-Lussac's law Combined gas law Avogadro's law Ideal gas law

瞳孔扩散意味着什么	出挑是什么意思	发烧喝什么汤	嗓子疼有痰吃什么药	手心脚心热吃什么药
气泡音是什么意思	肾虚吃什么食物能补	补体c3偏高说明什么	什么叫增强ct	不以为意什么意思
右眼跳什么	高铁与动车的区别是什么	什么食物含维生素c最多	枸杞泡茶喝有什么功效	护照办理需要什么材料
新奇的什么	做春梦是什么意思	龟头炎看什么科	汗斑用什么药	饱和脂肪是什么意思

棠字五行属什么hcv9jop2ns4r.cn	11月9号是什么星座hcv7jop5ns2r.cn	突然头晕是什么原因hcv8jop6ns4r.cn	神经外科和神经内科有什么区别hcv9jop6ns9r.cn	巴结是什么意思jingluanji.com
讣告什么意思hcv9jop2ns1r.cn	双侧卵巢多卵泡是什么意思hcv9jop7ns2r.cn	adl是什么意思hcv8jop1ns8r.cn	幼儿十万个为什么hcv9jop3ns8r.cn	澳门买什么最便宜hcv8jop2ns1r.cn
中线是什么意思hcv9jop0ns3r.cn	脑白质疏松症是什么病hcv8jop9ns4r.cn	什么是大健康产业hcv8jop7ns2r.cn	中元节又叫什么节hcv7jop6ns0r.cn	肌瘤是什么jiuxinfghf.com
什么什么本本dajiketang.com	强高是什么意思hcv8jop5ns5r.cn	国印是什么意思hcv7jop9ns1r.cn	解语花是什么意思xianpinbao.com	月经提前量少是什么原因hcv7jop9ns4r.cn