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These elements do not exist as single atoms. they are gases which always appear as a pair of atoms when they're naturally occurring.
Prefixes 1) mono 2) di 3) tri 4) tetra 5) penta 6) hexa 7) hepta 8) octa 9) nona 10) deca
These are all placed before each atom to indicate the number of atoms in the molecule
UNLESS the first atom in the equation is only ONE you dont set the prefix as "mono" you just leave it as it is. EX:
They can both achieve full valence shells by SHARING their electrons this is allowed because the electrons being shared belong to both of them at the same time
The formulas of ionic compounds can be reduced.
If there is a common between the amount of ions you divide it by the GCF (greatest common factor) In this case the GCF is 2
Subscripts were divided by 2
Get the two ions you're dealing with, ex:
cross the charges. Although the metal stays first in the equation. (if the charge is 1, it does not need to be shown in the formula)
EX:
1) Aluminum 2) Aluminum Oxygen 3) Aluminum Oxide
This means the total positive charge + total negative charge = 0
This can be put into an equation:
ex: FeO
In this ex we need to determine the charge of the Iron Ion Since we know the overall charge of an Ionic Compound is zero we can create an equation to find the unknown value by subbing in the charge of an Oxygen Ion (-2)
let X represent the unknown charge (iron)
MultiValent Metals In Ionic Compounds
When naming ionic compound formulas with multivalent metals, you must indicate which ionic charge it is with roman numerals
Metals that have multiple ionic charges:
Some Examples:
Fixed Valence Metals In Ionic Compounds
Fixed valence metals in ionic compounds are metals that have one ionic charge
Lithium is a fixed Valence Metal meaning its only ionic charge is Li+1
Ionic Compounds with radicals (polyatomic)
2 or more atoms that are contently bonded together and have an overall charge
Naming with Polyatomic Ions
1) Name the Metal (unless NH3 is in the equation, then that is named first because it is a cation) 2) Name the Polyatomic Cation the ending does not need to be changed (unless the equation is NH3 followed by a non metal)
ex: Mg (OH)2 1) Magnesium 2) Magnesium Hydroxide
Formulas with Polyatomic Ions
You place brackets around the polyatomic ion if there is more than one
This is important because it indicates in the example above that there are 2 hydroxide ions. Without it would appear there are 2 hydrogen ions ** Brackets should only be used if there is MORE THAN ONE polyatomic ion