Bonding Flashcards
When does ionic bonding occur?
-Between metals and non-metals
-Donating of electrons to form 2 full outer shells
-Forms a positive and a negative ion
What are the properties of ionically bonded compounds?
-Solid at room temperature
-High melting points
-Giant lattices
-Conduct electricity when molten or in solution
-Brittle
What are the five common ionic compounds?
-Ammonium=NH+
-Carbonate=CO3 2-
-Hydroxide=OH-
-Nitrate=NO3-
-Sulfate=SO4 2-
When does covalent bonding occur?
-Between non-metals
-Shared pair of electrons
-Form molecules, eg. Cl2 and methane
What are the properties of graphite?
-Weak bonds –> layers can slide over each other –> slippery
-Delocalised electrons
-Low density
-Very high melting point –> strong covalent bonds
-Insoluble
What are properties of diamond?
-Very high melting point
-Very hard
-Thermal conductor
-Can’t conduct electricity
-Insoluble
What is a co-ordinate bond?
Covalent bond but one atom provides both of the shared electrons, eg. ammonium ion
What is a charge cloud?
-Bonding pairs and lone pairs
-Whizz around, don’t stay still
How do charge clouds affect bond angles?
-Lone-pair charge clouds repel more than bonding-pair charge clouds
-Bond angles often reduced as bonding-pairs are pushed together by lone-pair repulsion
Name the sizes of bond angles due to electron pair repulsion.
-Lone pair/lone pair= biggest
-Lone pair/bonding pair
-Bonding pair/bonding pair= smallest
How many bonding/lone pairs does a tetrahedral have?
-4 bonding pairs
-0 lone pairs
What shape is a CO2 molecule?
Linear
What is the definition of electronegativity?
The ability to attract the bonding electrons in a covalent bond
When do non-polar bonds form?
When the atoms have equal electronegativity
When are molecules polar?
-Charge distributed unevenly over the molecule
-Causes a permanent dipole-making it a polar molecule
