How do we write the chemical formula for metals & non-metals?
Metals: chemical formula = atomic symbol
Non-metals: note diatomic molecules (HNFOICB) where chem formula = X2; otherwise chem formula = atomic symbol
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How do we write the chemical formula for covalent compounds?
Name of compounds gives the elements present
Prefix gives the no. of atoms of each element
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How do we write the chemical formula for ionic compounds?
Deduce the charge of the cation and anion (from PT)
Determine if the charges cancel out to zero. If yes, simply combine the ions.
Otherwise, cross-multiply each ion with the number on the charge of the opposite ion.
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What are some tips for balancing equations?
Hack 1: balance foreign atoms first (not H or O)
Hack 2: balance polyatomic ions as a whole unit
Hack 3: use fractions
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