what are oxidation numbers/ states?
numbers that represent the total number of electrons transferred to or from an atom within the compound
what oxidation number do uncombined elements (elements on their own) have?
0
what oxidation do atoms bonded to identical atoms (eg. O2) have?
0
what is the oxidation number for a monatomic ion (eg. Fe3+) ?
identical to its charge
eg. the oxidation number for Fe3+ is +3
where are the signs +/- placed for oxidation numbers ?
before the number
what is the oxidation number for O?
-2
what is oxidation number for H?
+1
what is oxidation number for F?
-1
what is oxidation number for Na+ and K+ ?
+1
what is oxidation number for Mg2+ and Ca2+?
+2
what is oxidation number for Cl-, Br-,I-?
-1
what is oxidation number for H in metal hydrides?
-1
what is oxidation number for O in peroxides?
-1
what is oxidation number for O bonded to F?
+2
what is another rule for combine atoms ?
sum of oxidation numbers = total charge
look at worked examples.
what do roman numerals in names of compounds show?
the oxidation state of the element without a sign.
eg. iron(III) represents Fe3+ with oxidation number +3
