Bonding, structure, and the properties of matter Flashcards
What are the features of solids?
- Particles are packed together in a REGULAR PATTERN w/ NO SPACES. - Fixed shape cannot flow particles can only VIBRATE.
What do elements try to achieve when they react?
A FULL OUTER ENERGY LEVEL (noble gas).
Describe what would happen between sodium and chlorine. (4)
…..23………35.5..
Na……….Cl……….
…..11…………17…….
- One electron
- Passes from the sodium atom
- To the chlorine atom
- Both atoms achieve a full outer energy level
Name 2 key properties of ionic compounds.
- They have VERY HIGH melting and boiling points.
- The strong ELECTROSTATIC FORCES require a GREAT DEAL OF HEAT ENERGY TO BREAK.
Why can ions not conduct electricity when solid?
Because the IONS CANNOT MOVE (localised). They are locked in place by the STRONG ELECTROSTATIC FORCES OF ATTRACTION.
How are ions arranged?
In a GIANT IONIC LATTICE where every POSITIVE ion is SURROUNDED by NEGATIVE ions.
Name 2 key properties of small covalent molecules.
- They have LOW melting and boiling points.
- They are usually GASES or LIQUIDS at room temperature.
What forces are there between covalent molecules?
INTERMOLECULAR forces.
Why can small covalent molecules not conduct electricity?
As they do NOT have an overall ELECTRIC CHARGE.
What state are giant covalent molecules at room temperature?
They are ALWAYS SOLIDS at room temperature
What can we say about giant covalent molecules bonds?
They have MILLIONS OF STRONG COVALENT BONDS.
What are giant covalent molecules melting and boiling points like?
They always have HIGH melting and boiling points.
What is diamond mostly made up of?
Carbon.
How many covalent bonds does carbon form in diamond?
4 (BREAKING these bonds requires a great deal of ENERGY.)
Can diamond conduct electricity and why?
No - there are NO FREE ELECTRONS to carry electrical charge.
Why does silicon dioxide have a very high melting and boiling point.
As a huge number of strong COVALENT BONDS must be broken and this takes a great deal of ENERGY.
How many covalent bonds does carbon form in graphite?
3 (HEXAGONAL RINGS - rings of 6 carbon atoms).
How are the hexagonal rings of carbon atoms arranged in graphite?
In LAYERS.
What do the layers allow and what does this make graphite?
They can SLIDE which makes graphite SLIPPERY.
Can graphite conduct electricity and how?
Yes - as it contains DELOCALISED ELECTRONS which can MOVE and conduct HEAT ENERGY and ELECTRICITY.
Is graphite a metal and why?
No - as it is based on the element CARBON.
Why is graphite and metals good conductors of heat and electricity?
As both graphite and metals have DELOCALISED ELECTRONS that can MOVE.
What is graphene?
It is a SINGLE LAYER of graphite. ONE ATOM THICK
Can graphene conduct electricity if so how?
Yes - as it has delocalised electrons.
