12141782
Description
Flashcards by Noah Cliff, updated more than 1 year ago
|
Created by Noah Cliff
almost 7 years ago
|
|
| Question | Answer |
| What are the properties of simple covalent molecles? | Although the atoms in the molecule are held together by strong electrostatic forces the molecules themselves are only held together by weak intermolecular forces. Resulting in low Boiling and melting points. Simple covalent molecules are not conductors of electricity as they have no overall charge and no delocalised electrons no. |
| Complex covalent molecules. | These are called polymers and they are a creation of a large chain of monomers. For example, the monomer ethene is joined up and the prefix poly is added to the name to make it polyethene. (Polymers tend to be joined together by carbon atoms as they can form up to 4 covalent bonds) Longer polymers have a larger intermolecular force so they also have a higher melting point than shorter polymers. |
| What are allotropes? | It is when an element can form a number of different structural forms. |
| What are the allotropes of carbon? Name their features. | 1. Fullerenes- these are simple carbon molecules and usually are spherical or are carbon nanotubes. They have weak intermolecular forces resulting in low boiling and melting points. However, the molecules themselves are very strong due to their covalent bonding 2. Graphene is not a simple molecule it is a sheet of carbon molecule bonded together with no fixed formular. The sheet is one atom thick but extremely strong. It has delocalised electrons as each carbon bonds with only 3 others (and it actually has 4 in the outer shell) this result in electrical conductivity. |
| Name two Giant structure of carbon and state their properties. | Graphite- Graphite is made of sheets of carbon stacked on top of one another held together by weak intermolecular force. Although it is weak and easy to break, as the sheets can slide over one another, it still has a high melting point as it's covalent bonds are still very strong. Due to only bonding with three other carbon molecules there are delocalised electrons that can conduct electricity. Diamond- Every carbon atom in the diamond is bonded to 4 other carbon atoms leaving no delocalised electrons therefore diamond does not conduct. Due to its rigid structure it is very hard. |
| Metallic structure and bonding | The atoms in a metallic lattice are all the same size and packed together in a lattice. The metal atoms have from 1-3 electrons in the outer shell all of these are released leaving a positively charged lattice in a sea of negative electrons. The electrostatic attraction between the positively charged ions and the electrons. This attraction is so strong that they have high melting and boiling points. |
| Properties of Metals | Metals are malleable which means they can be hammered into a shape without shattering. They also conduct electricity due to the delocalised electrons. The conductivity of a metal increases as the number of delocalised electrons increases. |
Want to create your own Flashcards for free with GoConqr? Learn more.