Chemisty Gcse Revision

[Gemby!]

Originally posted by Rat Faced@10 December 2003 - 14:41
The same compound always contains the same elements combined together in the same proportion by weight.

According to atomic theory, a compound is formed by the combination of definite number of atoms of different elements. Since each atoms has its own characteristic weight, the relative weight of each component in the compound must always be the same and, therefore, in every pure sample of the same compound, the elements must always be present in the same proportions by weight.

So for example, a molecule of water will always have the same weight as another molecule of water, as the proportions of Hydrogen atoms and Oxygen atoms will be identicle.

i got double award BUT we have these things called module tests which we do everytime we learn something about ''atoms and space '' or something like that which eventually goes towards my final grade

my final exam conmsists of all the modules - which equal biology physics and chemistry

[Rat Faced]

Originally posted by Rat Faced@10 December 2003 - 14:20
A molecule is the smallest unit of a compound that remains that compound.

If you break molecules of water, for example, into their atoms, you no
longer have water: you have hydrogen and oxygen.

I already told you

[3rd gen noob]

Originally posted by Rat Faced@10 December 2003 - 13:45
Heavy water is a different compound

well, the molecular and structural formulae for 'normal' water and 'heavy' water are exactly the same
the only difference is within the hydrogen atoms, so technically, they're the same compound

[Gemby!]

can i just say wow - im actually having a science related conversation - this is a first i think

mums gonna be proud !

[Rat Faced]

"Heavy Water" is deuterium oxide.

D2O, as opposed to H2O.......ie a different compound

Deuterium Oxide

[3rd gen noob]

Originally posted by Rat Faced@10 December 2003 - 13:55
"Heavy Water" is deuterium oxide.

D2O, as opposed to H2O.......ie a different compound

i wasn't aware deuterium was a seperate element

well, you learn something new every day

(maybe i was right to give up chemistry)

[Proper Bo]

Could you please not confuse the poor lad with this "heavy water" crap, it has nowt to do with his GCSE at all


EDIT: dear god! Did i just type the word "nowt"?

[3rd gen noob]

Originally posted by Proper Bo, I tell thee@10 December 2003 - 13:58
Could you please not confuse the poor lad with this "heavy water" crap, it has nowt to do with his GCSE at all

what are you struggling with in particular then?

[Proper Bo]

I'm not struggling with anything thankyou, i did my GCSE's last year

[Rat Faced]

Originally posted by 3rd gen noob+10 December 2003 - 14:56--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (3rd gen noob @ 10 December 2003 - 14:56)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-Rat Faced@10 December 2003 - 13:55
"Heavy Water" is deuterium oxide.

D2O, as opposed to H2O.......ie a different compound

i wasn&#39;t aware deuterium was a seperate element

well, you learn something new every day

(maybe i was right to give up chemistry) [/b][/quote]
It isnt

But we&#39;re talking GCSE here, not BSc