Boiling and Melting points

Why is it that for some elements, you say that you need to break the intermolecular forces for it to boil or melt e.g. Chlorine but for others you have to break covalent bonds e.g. carbon. Does carbon not have any intermolecular forces?? or are the intermolecular forces only possible between molecules and a carbon atom isnt a molecule???


Please reply! got a mock tomorrow

i understand the difference between inter and intra. i just want to know why you have to break the covalent bonds in carbon for it to boil and not intermolecular forces like Cl2. does carbon not have intermolecular forces?

When you say carbon, do you mean just as an atom? Or would you mean graphite ?The intermolecular bonds are still present in the case of graphite it holds the layers together but these forces are weak as compared to strong intramolecular giant covalent bonds

i mean as an atom. carbon on its own is monatomic so this would mean it doesnt have any intermolecular forces. but chlorine is diatomic so it does?

are intermolecular forces only possible with atoms that are diatomic??

http://intro.chem.okstate.edu/AP/Lec83101.html
Van der Waal intermolecular forces do exist between monoatomic substances...noble gases

i mean as an atom. carbon on its own is monatomic so this would mean it doesnt have any intermolecular forces. but chlorine is diatomic so it does?

are intermolecular forces only possible with atoms that are diatomic??

May I?

When considering melting points why are you considering monatomic carbon? carbon doesn't exist like that other than under extreme lab conditions.

Elemental carbon is macromolecular whether you consider graphire or diamond. A pieve of elemental carbon is effectively a single molecule. So there aren't intramolecular forces to breakdown - all the attraction forces that require breaking down are intramolecular, they are covalent bonds.

Boiling point of carbon is high because you need to melt it first.

so carbon is always in a big structure. okay but how about other elements such as silicon? do they also only exsist as large structures so they dont have any intermolecular forces but covalent bonds

Yes silicon is also macromolecular.

Learn your common macromolecules, you will need to know these to understand or predict melting point or boling point trends and more

just to make sure please.

Any element which is macromolecular will need covalent bonds to be broken when melted or boiled. this is because one of them is monatomic so there are no intermolecular forces

Thank you for your help!