C2.2 How structure influences the properties and uses of substances Flashcards
Do simple molecules conduct electricity?
No
Why do simple molecules not conduct electricity?
because the molecules do not have an overall change
Why do ionic compounds have high melting and boiling points?
as there are strong electrostatic forces in all directions between oppositely charged ions. Large amounts of energy are needed to break many strong bonds
When can ionic compounds conduct electricity, why?
when melted or dissolved in water.
can conduct electricity because ions can move and carry a current
give an example of an ionic compound
sodium chloride
Why do giant covalent structures- macromolecules, have high boiling and melting points?
As all atoms are linked to other atoms by strong covalent bonds.
How many covalent bonds does carbon form in diamond?
4
How many covalent bonds does carbon form in graphite?
3
Why are there layers in graphite?
As each carbon atom bonds to 3 other carbon atoms
Why is graphite soft and slippery?
each carbon bonds with 3 other carbon atoms which forms layers. Layers are free to slide over each other as there are no covalent bonds between the layers so therefore weak intermolecular forces between layers.
Why can graphite conduct electricity?
One electron from each carbon atom in graphite is delocalised. These delocalised electrons allow graphite to conduct heat and electricity
Describe the structure of fullerenes
hexagonal rings of carbon atoms
What can fullerenes be used for?
drug delivery into the body. in lubricants, as catalysts, and in nanotubes for reinforcing materials eg in tennis rackets
What does conduction depend on?
the ability of electrons to move throughout the metal
Why do metals conduct heat and electricity?
because of the delocalised electrons in their structures