Bonding Flashcards
Covalent bonding
Bonding between two non-metals.
Ionic bonding
Bonding between metals and non-metals
Metallic bonding
Bonding between metals
What is the objective in bonding?
To get a full outer shell to make it more stable (structure of a noble gas)
What is the structure of ionic compounds?
Giant ionic lattice (regular lattice arrangement)
What are the properties of ionic compounds?
> High melting and boiling points due to the many strong forces of attraction between oppositely charged ions
Can ionic compounds conduct electricity?
Not when solid but when melted they can as ions are free to move. Some can also dissolve in water so would then carry electricity
Problems with the dot and cross diagrams:
Don’t show the relative sizes of the atoms or how the atoms are arranged in space
What are simple molecular substances?
Molecules containing a few atoms joined together by covalent bonds
Do simple molecular substances conduct electricity?
No as they are aren’t charged so there’s no free ions
What state are simple molecular substances normally at room temperature?
Gas or liquid
High or low boiling point in simple molecular substances?
Low as there is a weak force of attraction and not many covalent bonds.
Diamond
> Each carbon atom makes 4 covalent bonds making diamond really hard
Strong covalent bonds make diamond have a high boiling point
Doesn’t conduct electricity as there are no free electrons or ions
Graphite
> each carbon atom only makes three covalent bonds that create sheets of carbon atoms arranged in hexagons
no covalent bonds between layers so they can slide over each other (ideal lubricating material)
high melting point as covalent bonds in layers need lots of energy to break
conducts electricity + thermal energy as there is one delocalised electron per carbon atom
Graphene
> one layer of carbon (the sheet is just one atom thick)
very strong due to covalent bonds but very light
contains delocalised electrons so has potential to be used in electronics
