<p>Of the following pure substances, which has the highest melting point?</p>
<p>S8
I2
SiO2
SO2
C6H6</p>
<p>It’s silicon dioxide, but I don’t know why</p>
<p>closer to an ionic </p>
<p>ionic >>>>> non metal</p>
<p>SiO2 because it is a network covalent substance (it is quartz, structurally similar to diamond)</p>
<p>…what does that have to do with melting point? Sorry, I don’t know this stuff…</p>
<p>Well, I am not sure about the specifics but imagine how hard it would be to melt diamond. This is because it a network covalent substance, like SiO2.</p>
<p>4 Different types of solids :
-Network Covalent (diamond)
-Ionic (salt)
-Molecular (sugar)
-Metallic (iron, chromium, etc.)</p>
<p>In order of increasing melting point I believe it goes</p>
<p>Molecular, Ionic, Metallic, Network Covalent</p>
<p>Someone correct me if I am wrong</p>
<p>i believe its Molecular < Metallic < Ionic < Covalent Networking. toastmaster, just remember that whenever you see silicon, its Covalent Networking.</p>
<p>Yes, it is Molecular<Metallic<Ionic<Network Covalent</p>
<p>Thanks for the correction</p>
<p>With network solids, you have to overcome actual bonds between molecules, not just intermolecular attractions. While those other substances would just be held together by intermolecular forces as discreet molecules, SiO2 would form a giant interlocking network of bonds between atoms, like diamond.</p>
<p>Any of you have an specific tips for MC part of the test? Er i think i might have to take monday off, I am not ready!</p>