6.2 Names and Formulas of Common Compounds
Common Names and Chemical Names
Common names can be confusing when naming compounds
Inaccurate and provides no hint of elements present
Chalk
writing chalk (calcium sulfate)
Antacids (calcium carbonate) – also in sea shells, snail shells, eggshells
Every compound has a name and formula
Chemical formula – identifies which elements, and how much of each are in the compound
Ion Charges
Ion notation – element symbol with a superscript and a + or – sign at the top right
Some metals are able to form more than one type of ion (have more than one charge)
A Roman number is included in the ion name to show the ion charge
(I) = 1 (II) = 2 (III) = 3 (IV) = 4
Non-metals Name of non-metal changes to ‘ide’ at
the end
Naming Ionic Compounds
Rules 1) Name the metal ion first (simply the
element name). **If an element can form more than one
kind of ion, include the Roman number to indicate the charge.
2) Name the non-metal second. Change the ending to ‘ide’.
**subscripts (small #) are ignored for naming compounds
Multivalent Elements
For elements that can make more than one ion
You can find the Roman # to use by using the subscripts in the formula
This is written in the middle of the compound name
Writing Formulas for Ionic Compounds
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