Categorie: Tutti - prefixes - ionic - molecular - covalent

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Nomenclature

Covalent compounds are formed when elements share electrons, often involving special prefixes to indicate the number of atoms present. For example, CO2 is named carbon dioxide. Molecular compounds, which consist of nonmetals sharing electrons, also follow similar naming conventions.

Nomenclature

Nomenclature

Drawing

Bohr Rutherfords
These are diagrams that show elements electrons from the inner to the outer shell An electron has two electrons in it's first, eight in the second eight in the third and then it gets more complicated from their. You draw lines from the outer shell to the shell of the other atom when drawing it for bonds and compounds.
Lewis Dot diagrams
These are simpler diagrams than bohr rutherfords. You only draw the valence electrons, in dots around the chemical symbol. And then draw connections with arrows to show if an electron has been lost or gained when being used for compounds.

Example

Lewis Structures
Lewis structures are a simple ways for showing the valence shells in an atom. These are usually used when drawing molecular compounds. Draw lines to the atoms to show they are being shared.

Example: Carbon Dioxide

Indicating Charge

Factoring
Factor out the numbers to reduce them to the lowest possible value. If they don't have one you can just leave it alone.

Example: Octane

Criss Cross
Cross the charge from the second element to the other and vice versa, this will help you determine the number of atoms in a compound. This is the method I prefer as I believe it's the fastest.

Example: Sodium Phosphide

If it's a multivalent un cross the numbers to get their charge they specify the multivalent metal by indicating it's charged by a roman numeral.

Zero Sum
Find the number of atoms that would balance it out. that cancel out to zero between the numbers, and that will be your final answer. Say you have something with a positive +4 charge and a -5 charge. You would need 5 of the first and 4 of the second to make the sum of them both multiplied together to be zero.

Periodic Table

Something to show you all the elements on the periodic table. The colors indicate what kind of element it is, check the legend below it. (To expand, hover your cursor over the image then click the expand icon that appears in the top right corner).

Formulas

When writing formulas for compounds the metal goes before the non metal if there's one. And place the number of atoms used in the compound after the chemical symbol.
Ex. Octane= C8H18

Elements

Compounds