Ammonia is NH3. It is a compound and a gas.
Ammonium is NH4+1. It is an ion and is in water solution.
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The Diatomic Elements
These have two atoms per molecule when FREE.
H2, O2, N2, Cl2, Br2, I2, F2
Acids:
Acetic HC2H3O2 .................... Nitric HNO3 .................... Hydrochloric HCl
Phosphoric H3PO4 ............... Sulfuric H2SO4 ............... Sulfurous H2SO3
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Subscript Symbols
(c) crystal, (aq) aqueous, (s) solid, (g) gas
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Types of Chemical Reactions
Synthesis-- Putting together (elements making compounds).
2H2 + O2 ---> 2 H2O
Decomposition-- Taking apart (compounds making elements).
2NH3 ---> N2 + 3H2
H2SO4 ---> H2 + S + 2O2
Single Displacement-- An element replaces another element from a compound.
Zn + 2HCl ---> ZnCl2 + H2
Double Displacement-- Two compounds exchange partners.
2 AgNO3 + K2CrO4 ---> 2KNO3 + Ag2CrO4
Hydrolysis means add water. + H2O or HOH.
2Na + 2HOH ---> 2NaOH + H2
Combustion (burn it)-- Add O2 and get CO2 & H2O
CH4 + 2O2 ---> CO2 + 2H2O