Structure And Physical Properties Flashcards
What are the physical properties of a simple molecular substance.
1) they are liquids or gases at room temperature and have weak intermolecular forces unlike solids.
2) low melting and boiling point usually below 200 degrees celsius
3) many have very low boiling point due to their weak intermolecular forces resulting in them being volatile and easily evaporating in air.
4) they do not conduct electricity
5) they only dissolve in organic compounds organic compounds are carbon compounds
What are the physical properties of giant molecular substances?
1) all of them are solids.
2) they have very high melting and boiling point this is because of the strong covalent bonds.
3) they do not conduct electricity except graphite.
4) they are insoluble in any solvent.
Why is graphite the only non metal that conducts electricity?
It can conduct electricity because in each layer of graphite one carbon atom is covalently bonded to three other carbon atoms leaving one delocalised electron. The delocalised electron then moves in between graphite and therefore has the ability to conduct.
What are the physical properties of ionic compounds?
1) ionic compounds are hard crystalline solids. The crystals have flat sides and regular shapes the ions are arranged in straight rows. the rows form a large structure with flat sides the ions are held in a place by strong ionic bond which make the Crystal hard.
2) most ionic compounds have high boiling and melting point. To break their ionic bonds a lot of heat is needed.
3) they are not volatile hands making them smell less.
4) they can not conduct electricity however when in molten or dissolved in water the electrons can move freely resulting in them being able to conduct electricity but only in molten form or when dissolved in water
5) many ionic compounds are soluble in water. This is because of the attraction of water and ions causing the iron to separate and going to the solution.
It can only be soluble in aqueous solution as in tetrachloromethane it does not dissolve thus water is required.
What are the physical properties of metallic structure?
1) they are malleable and ductile malleable means they can be bent and ductile means they can be stretched they are ductile because the layers in the structure can rub against each other when you apply force to them and they do not break because they are strong metallic bonds.
2) they have very high melting and boiling points due to the strong metallic bonds.
3) all metals are good conductors of electricity since they have a free electron in the sea of electrons.
4) they are good conductors of heat as when a metal is heated the delocalised electrons gain energy hitting against other electrons therefore transferring the heat.
