Learing Chemical Formulas

Hi there
Im new to chemistry so if anyone could help me that would be great

please note i dont have a chemistry text book or anything

could someone explain why nitrogen dioxide is N02 when the valancy of nitrogen is 3 do we just ignore the 3

also in AGNO3 (Silver Nitrate) I know a nitrate is NO3 but do we have to worry about the valancy of the silver or anything

because the valancy for silver is 2 and the valcy for nitrogen is 3 if i am correct

thanks for your help

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Actually, Nathan, the valency (note the spelling) of nitrogen varies. In the compound NO[sub]2[/sub] we have N[sup]+4[/sup] and O[sup]-2[/sup]. As a compound, the charges neutralize so the effective charge of NO[sub]2[/sub] is 0. The valence of N in the nitrate ion is N[sup]+5[/sup]; with 3 O[sup]-2[/sup] we have a net equivalent charge if NO[sub]3[/sub][sup]-1[/sup], so the valence of silver is Ag[sup]+1[/sup].

There are plenty of good chemistry texts out there; try your public library and of course shop around at used book stores for a good deal. Some texts may be a few years old, but the nice thing about science is that basic facts rarely become obsolete. All of my chemistry books are pre-Mendeleev, but soon we will be inundated by suggestions for reliable recent texts; then we both can surf abebooks.com and find a bargain in an upto date chemistry text. You really should get one. :wink:


hi thanks for your help with my valency questions, sorry bout they spelling mistake

yes tommorrow i am checking out my local libary for what books they have on chemistry

do you know any good websites
thanks heaps with your help im progressing well throughout my worksheets

although i must say i enjoy physics much more than chemistry lol


Also a note... if you've to make nitrogen stable, it has to have a -3 , 5 oxidation or 3 valence.

The 4 oxidation number in NO2 therefore makes the compound unstable. (therefore it comes with an unusual brown colour)

i don't see how the color derives from the stability, beside the NO[sub]2[/sub] in the LA air just hangs there. :lol:

i think its brown color comes because it is so unstable that it bends light.

light is refracted through substances that slow it down or deflected by intense gravitational fields, neither of which is correlated with the stability of a molecule.

But why did the other colours disappear?

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