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lattice in chemistry

can i ask if lattice shows all atoms involved in that particular matter? Or is it just small proportion which shows its arrangement?

thanks :smile:
Original post by BrightBlueStar11
can i ask if lattice shows all atoms involved in that particular matter? Or is it just small proportion which shows its arrangement?

thanks :smile:

Usually just a small proportion. It’s arrangement would be the same throughout the whole substance, so no point in showing all the atoms. Also, even small amounts of matter have gazillions of constituent atoms, so practically impossible to show all of them in 1 diagram.
Original post by ChameleonChem_
Usually just a small proportion. It’s arrangement would be the same throughout the whole substance, so no point in showing all the atoms. Also, even small amounts of matter have gazillions of constituent atoms, so practically impossible to show all of them in 1 diagram.


oh ok it makes sense thanks :smile:

and also, in the case of diamond, i noticed that it is a pyramid-shaped? is it just showing the tip of the diamond?
Original post by BrightBlueStar11
oh ok it makes sense thanks :smile:

and also, in the case of diamond, i noticed that it is a pyramid-shaped? is it just showing the tip of the diamond?

Not necessarily the tip. I think it’s pyramid shaped because the simplest ‘sub-unit’ of a diamond is a central carbon atom with 4 carbon atoms bonded around it (see below). Because of VSEPR theory, this has a tetrahedral or pyramid like shape. I believe the lattice model is just emulating this.


Another thing to mention is that the diamond lattice doesn’t necessarily have to be pyramid shaped. Take, for example, below:

Original post by BrightBlueStar11
in the case of diamond, i noticed that it is a pyramid-shaped? is it just showing the tip of the diamond?


I think you might be visualising diamond in its cut, polished form?

Remember that diamond is one of the allotropes of carbon. In diamond, each carbon atom forms a total of 4 covalent bonds, with 4 other carbon atoms. So when you're drawing the giant covalent lattice of diamond, you want to show this. It would be silly to try to draw out every single carbon atom and all the bonds in a chunk of diamond (and anyway the size of a piece of diamond varies), so instead we only show a small portion of it, while still conveying all the necessary information about the structure.

Here's a useful page: https://chemguide.co.uk/atoms/structures/giantcov.html
(edited 1 year ago)

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