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Date: 2-8-2020
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Date: 11-7-2018
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Date: 22-11-2020
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Recall that a molecular formula shows the number of atoms of each element that a molecule contains. A molecule of water contains two hydrogen atoms and one oxygen atom, so its formula is H2O . A molecule of octane, which is a component of gasoline, contains 8 atoms of carbon and 18 atoms of hydrogen. The molecular formula of octane is C8H18
.
Figure .2 : Nitrogen dioxide (NO2) is a reddish-brown toxic gas that is a prominent air pollutant produced by internal combustion engines.
Naming binary (two-element) molecular compounds is similar to naming simple ionic compounds. The first element in the formula is simply listed using the name of the element. The second element is named by taking the stem of the element name and adding the suffix -ide. A system of numerical prefixes is used to specify the number of atoms in a molecule. Table .1
lists these numerical prefixe
Number of Atoms in Compound | Prefix on the Name of the Element |
---|---|
1 | mono-* |
2 | di- |
3 | tri- |
4 | tetra- |
5 | penta- |
6 | hexa- |
7 | hepta- |
8 | octa- |
9 | nona- |
10 | deca- |
*This prefix is not used for the first element’s name.
Note
. The order of common nonmetals in binary compound formulas is C, P, N, H, S, I, Br, Cl, O, F
Some examples of molecular compounds are listed in below Table
Notice that the mono- prefix is not used with the nitrogen in the first compound, but is used with the oxygen in both of the first two examples. The S2Cl2 emphasizes that the formulas for molecular compounds are not reduced to their lowest ratios. The o of the mono- and the a of hepta- are dropped from the name when paired with oxide.
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للتخلص من الإمساك.. فاكهة واحدة لها مفعول سحري
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العلماء ينجحون لأول مرة في إنشاء حبل شوكي بشري وظيفي في المختبر
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العتبة العباسية تحتفي بذكرى ولادة السيدة الزهراء (عليها السلام) في محافظة واسط
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