Except pure alloys, are there any compounds with more metal elements proportion of atoms than nonmetal elements in proportion of atoms? [closed]








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Except pure alloys, are there any compounds with more metal elements in proportion of atoms than nonmetal elements in proportion of atoms?


For example, Aluminium oxide has 2 metal elements & 3 nonmetal elements. Do we have a compound with X metal elements & Y nonmetal elements, where Y is more then X.




There are some rare but very interesting cases in which two metals react when mixed instead of forming an alloy, creating a non-metallic compound made only with metal atoms. Examples are caesium auride ($\ce{CsAu}$), caesium platinide ($\ce{Cs2Pt}$) and several barium platinides ($\ce{BaPt}$, $\ce{Ba2Pt}$, $\ce{Ba3Pt2}$, and possibly others), all of which best described as ionic salts rather than alloys. These are [a remarkable consequence of relativistic effects in heavy atoms](http://www.sciencedirect.com/science/article/pii/S129325580500230X).


 7

In addition to the answers by Nicolau and DrMoishe.


Most prominent examples are the binary oxides of the alkali metals $\ce{A2O}$: [lithium oxide](http://en.wikipedia.org/wiki/Lithium_oxide) $\ce{A~=~Li}$, [sodium oxide](http://en.wikipedia.org/wiki/Sodium_oxide) $\ce{A~=~Na}$, [potassium oxide](http://en.wikipedia.org/wiki/Potassium_oxide) $\ce{A~=~K}$, [rubidium oxide](http://en.wikipedia.org/wiki/Rubidium_oxide) $\ce{A~=~Rb}$ and [caesium oxide](http://en.wikipedia.org/wiki/Caesium_oxide) $\ce{A~=~Cs}$.  

Of course there are also higher homologs of these compounds like [lithium sulfide](http://en.wikipedia.org/wiki/Lithium_sulfide) $\ce{Li2S}$. 


Especially for rubidium and caesium there are also a number of [suboxides](http://en.wikipedia.org/wiki/Suboxide), i.e. $\ce{A9O2}$ and others. This is a whole class of compounds whith a rich variety.


There are also the nitrides of the alkali and earth alkali metals, e.g. [lithium nitride](http://en.wikipedia.org/wiki/Lithium_nitride) $\ce{Li3N}$ and [magnesium nitride](http://en.wikipedia.org/wiki/Magnesium_nitride) $\ce{Mg3N2}$. 


There are a couple of [phosphides](http://en.wikipedia.org/wiki/Phosphide) known, that fit your description, e.g. $\ce{K3P}$, $\ce{K4P3}$, $\ce{K5P4}$. These compound are also known from transition metals, like $\ce{Cu3P}$ or $\ce{Ni5P2}$.


Like the above, there are also some very common carbides, like [aluminium carbide](http://en.wikipedia.org/wiki/Aluminium_carbide) $\ce{Al4C3}$.


And I am very certain, there are many more.


 5

Sure, e.g. sodium aluminate, Na2Al2O4 (anhydrous formula), is a common chemical (it's the "gray stuff" on aluminum dishware cleaned in an automatic dishwasher with alkaline detergents).


 4

Petzite, $\ce{Ag3AuTe2}$, is an uncommon telluride containing mineral that seems to fit the bill.


Sodium oxide $\ce{Na2O}$ is well known, as is potassium oxide, rubidium oxide, etc.


Some one should write a parser and see if [this list from Wikipedia](http://en.wikipedia.org/wiki/List_of_inorganic_compounds) has any more examples. I didn't see any that weren't already mentioned here on a quick skim.


 3