| carbon isotope and uses | carbon-14, estimating the age of things that contain carbon |
| uranium isotope and uses | uranium-238, estimating the age of rocks |
| boiling and melting points for ionic compounds? | ionic compounds have high melting and boiling points because strong forces of attraction |
| solubility of ionic compounds? | ionic compounds are soluble in water (water molecules are attracted to ions) and insoluble in organic solvents |
| do ionic compounds conduct electricity | ionic compounds conduct electricity when molten or in aqueous solution only. free moving electrons |
| Boiling and melting points of simple molecular structures + explanation | simple molecular structures have low melting and boiling points because weak intermolecular forces exist between the molecules |
| solubility of simple molecular structures | simple molecular structures are soluble in organic substances and insoluble in water |
| conduction of electricity for simple molecular structures? | simple molecular structures do not conduct electricity in any state as there are no free moving ions |
| melting and boiling points for giant molecular structures? | giant molecular structures have high melting and boiling points, large number of atoms held together by strong covalent bonds |
| conduction of electricity in giant molecular structures? | giant molecular structures do not conduct electricity (except graphite) |
| solubility of giant molecular structures | subs with giant molecular structures are insoluble in both water and organic solvents |
| why is diamond hard and has a high melting point? | each carbon atom is covalently bonded to four other carbon atoms that in turn are bonded to four more carbon atoms. 3d structure and strong covalent bonds |
| why does diamond not conduct electricity | all the outer electrons of carbon atoms are used for bonding, no free moving electrons |
| why does graphite have a high melting and boiling point? | each carbon atom in graphite is bonded to 3 carbon atoms that in turn are bonded to 3 more carbon atoms, forming a layer of hexagons. strong covalent bonds |
| why is graphite soft and slippery? | the layers of carbon atoms are held loosely by weak intermolecular forces, these layers can slide over each other when force is applied |
| why does graphite conduct electricity? | each carbon atom has one spare electron that is not used in covalent bonding. these electrons can move freely past layers and are said to be delocalised |
| why does silicon dioxide have a high melting and boiling point | each silicon atom is bonded to four oxygen atoms and each oxyegn atom is bonded to two silicon atoms. 3d structure, strong covalent bond. |
| why does silicon dioxide not conduct electricity? | no free moving electrons |
| why are metals good conductors of electricity? | when atoms are tightly packed, the outer electrons can easily break away |
| why are metals good conductors of heat | the delocalised electrons can easily transfer heat energy |
| why do metals have high melting, boiling points and densities? | packed strongly together; strong metallic bonds |
| why are metals malleable and ductile | when force is applied, one layer of metal ions can slide over the other through the sea of mobile electrons |
| physical properties of metals? | metals are: malleable and ductile, have high melting and boiling points and densities, can conduct heat and electricity |
| properties of silicon dioxide | silicon dioxide cannot conduct electricity, has high melting and boiling point |
| physical properties of graphite? | graphite has a high melting and boiling point, is soft and slippery, can conduct electricity |
| physical properties of diamond | high melting and boiling point, cannot conduct electricity, |
| properties of ionic compounds | ionic compounds have high melting and boiling points, conduct electricity when molten or in aqueous state only, soluble in water and insoluble in organic solvents |
| properties of substances with simple molecular structures | simple molecular structures have low melting and boiling points, do not conduct electricity in any state, and are soluble in organic solvents only |
| properties of substances with giant molecular structures | giant molecular structures have very high melting and boiling points, are insoluble in both organic solvents and water, and do not conduct electricity |
