Qualification > Sciences
Chemistry Help!
hyebyekadal:
spontaneous reactions are reactions that occur at room temperature as their activation energy isn't very high. and displacement reactions are reactions in which a compound breaks down into 2 or more products.
astarmathsandphysics:
The force of attraction between of negative electrons and positive atoms
Keep everything together
emi:
thanks ,, but there was a definition about sea of electrons or delocalised electrons i really cant find a good definition for that one ,, if some one could tell .. and please i want all the aparatus names for the practicle my book dont have all of them because i've seen some in pastpapers that are not in my book .
thanks
astarmathsandphysics:
--- Quote from: Guthixol on April 29, 2009, 05:07:46 pm ---may you explain to me electrolysis in anyway you like to explain it. It helps me if i read someones explanation before i read the whole chapter. thanks :) oh oh..yeah may you explain acids and basis :P i get confused most of the times :-\
--- End quote ---
Electrolysis is used to purify ores. The ore forms the anode and the pure metal the cathode. The anode is connected to the postive terminal of a battery and postive ions of the substance to be purified dissolve from it into solution and move towards the cathode.
astarmathsandphysics:
--- Quote from: emi on April 29, 2009, 09:56:54 pm ---thanks ,, but there was a definition about sea of electrons or delocalised electrons i really cant find a good definition for that one ,, if some one could tell .. and please i want all the aparatus names for the practicle my book dont have all of them because i've seen some in pastpapers that are not in my book .
thanks
--- End quote ---
In metals, the metal atoms lose their outer electrons to form metal cations. The electrons from all the metal atoms form a "sea" of electrons that can flow around these metal cations. These electrons are often described as delocalised electrons - delocalised means "not fixed in one place" or "free to move".
Also explained more fully here.
http://www.chemguide.co.uk/atoms/bonding/metallic.html
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