Question

Assign oxidation numbers to each element in this compound.

MnO₂
@Kryten

Answer 1

How do I figure out the oxidation?

Answer 2

ok now here we need to start with few rules... do you have your chemistry textbook?

Answer 3

only an onlive one that is really hard to follow

Answer 4

ok do you have your periodic table at hand, not an online one but actual paper one?

Answer 5

Yes

Answer 6

ok now look at it and compare what i say... ill simplify rules untill you get them and then you can learn all "sub rules" more easily...
first group (Li Na K...) "always" has oxidation number +1 ie it gives one electron
seccond group "always" has oxidation number +2 ie it gives two electrons
7th group (F Cl Br...) "always" has oxidation number -1 ie it recieves one electron
6th group "always" has oxidation number -2 ie it recieves two electrons
get it so far?

Answer 7

so mn would have the -1?

Answer 8

no, for all metals and metaloids you determine oxidation number indirectly...
let me elaborate
now that we know that oxygen has oxidation -2 and we know that in molecule MnO2 we have two atoms of oxygen we can see that total oxygen recives 2 * 2 electrons which is 4 right, so if those two oxygens recive 4 electrons Mn has to let go of those 4 electrons right?
so Mn in this case has oxidation number +4 now while you read this ill draw you procedure...