[INeedSerotonin]

Hello

I found an exercise in which I had to attribute "covalent", "Van Der Waals" and "ionic" to the compounds. I was given "diamond", "naphthalene", and "magnesium oxide".

The answer is that diamond is covalent, naphthalene is Van Der Waals, and magnesium oxide is ionic.

However, this doesn't make sense to me. Shouldn't the diamond be both Van Der Waals and covalent? And shouldn't naphthalene be both too?

Thanks

[chenbeier]

No, diamond is a makro molecule of carbonatoms, so it has covalent bond between all C. Napthalen is a small molecule and several of them have van de Waals between each. The bonds in the molecule is covalent, but this was not the question.  The magnesium oxide is a ionic compound.
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[INeedSerotonin]

No, diamond is a makro molecule of carbonatoms, so it has covalent bond between all C. Napthalen is a small molecule and several of them have van de Waals between each. The bonds in the molecule is covalent, but this was not the question.  The magnesium oxide is a ionic compound.
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Thank you! If it were "graphite" or "fullerene" instead of "diamond", would the answer be the same?

Also, let me see if I understood it well: diamonds do not attract other diamond macromolecules with Van Der Waals forces? They all become one single macromolecule?

[jeffmoonchop]

If you google the crystal structures of each of these you'll be able to understand more about the intermolecular interactions. Comparing the structure of diamond and graphite you'll see how the covalent bonding in diamond prevents separation of layers like with graphite. The layers in graphite are covalently bonded into sheets, but what interactions do you think occur between layers? And do you think they are stronger than interactions between fullerene balls?