C3-Structure And Bonding Flashcards
What is covalent bonding
Between 2 non metals
Electrons are shared between the atoms so they have a full outer shell
They are strong and require alot of energy to break
Describe a covalent double bond
If an atom needs 2 electrons to complete its outer shell, it shares 2 electrons per atom to make a double bond
Why is a covalent bond strong
There is an attraction between the electrons and the positively charged nucleus
What is a molecule
A substance which contains two or more covalently bonded atoms
What is a lone pair
A pair of electrons thst are not part of the covalent bond
What are the properties of a simple covalent compound
Low melting point
Often gases at room temperature
What is the difference between the covalent bonds and intermolecular forces in simple covalent compounds
Covalent bonds are very strong
Intermolecular forces are weak
What is an ion
An atom with a positive or negative charge due to loss or gain of electrons
What is an ionic bond
A bond formed by the electrostatic attraction of oppositely charged ion
What is electrostatic
The force between a positive and negative charge
How does an ionic bond form
Electrons from outer shell of metal are transferred to the non metal atom
Metal is positive, non metal in negative
There is now an electrostatic force between them which forms an ionic bond
Describe an ionic lattice structure
Ionic compound have giant ionic lattices in which there are strong electrostatic forces of attraction in all directions between oppositely charged ions
Describe the properties of ionic compounds
High melting points due to strong electrostatic forces between oppositely charged ions-alot of energy is required to break them
Does not conduct electricity as a solid
Do conduct electricity is they are aqueous or liquid as ions are free to move
Properties of covalent compounds
Size of intermolecular force gets bigger as the molecules get larger
Do not conduct electricity as they have no free electrons to carry the charge
What is a polymer
A very large molecule made from monomers
Large covalent compounds
Properties of polymers
Higher melting points than smaller covalent compounds as intermolecular bonds are stronger
Bonds are not as strong as ionic or giant covalent compounds so melting points are lower than those compounds
What is metallic bonding
A type of binding that only occurs in metals
What is the structure of a metallic bond
Giant structure
Metal atoms form a regular pattern
Donate outer electrons to sea of demoralised electrons
What are the properties of metals
Good conductors of electricity due to delocalised electrons that carry charge
Good conductors of heat, free electrons carry energy
Malleable as the layers of ions can easily slid rover one another
What is an alloy
Mixture of 2 or more elements, one of which is a metal
Describe the structure of an alloy
The regular structure of metal is changed so the layers of ions can no longer slide over one another making it stronger
What is the order of the reactivity series
Please- Potassium
Send-Sodium
Lions-Lithium
Cats-Calcium
Monkeys-Magnesium
And-Aluminium
Zebras-Zinc
Into-Iron
Lovely-Lead
Hot-Hydrogen
Countries-Copper
Signed-Silver
General-Gold
Penguin-Platinum
What are the 3 giant covalent compounds
Diamond
Graphite
Silica
Describe diamond
Each carbon is covalently bonded to 4 other carbons
Very hard
Very high melting point due to strong covalent bonds
Does not conduct electricity-no free electrons
Describe graphite
Each carbon is covalently bonded to 3 other carbons
There are weak bonds between the layers
Hight melting point
Conductor of electricity due to delocalised electrons which carry charge
Slippery as layers can slide over eachother
Describe silica
Every silicon atom is bonded to 3 oxygen atoms and vice versa
High melting point
What is graphene
A single layer of graphite
1 atom thick
What are fullerenes
Molecules of carbon with hollow shapes
What are the uses of fullerenes
Drug delivery
Catalysts
What are carbon nanotubes
Cylinder shapes fullerenes
Strong
Good conductors of heat/electricity
What is a nonoparticle
A particle between 1nm and 100nm in diameter
Extremely large surface area
Catalyst
A substance which speeds up a reaction, by providing an alternate pathway, without being used up
What are the potential applications of nanoparticles in medicine
Targeted delivery of drugs-more easily absorbed, could be used to deliver drugs to specific tissues
Making synthetic skin
What are the other uses of nanoparticles
Silver nanoparticles have antibacterial properties
Some nanoparticles are electrical conductors
Can be used in cosmetics to make them less oily
Used in sun creams-provide better UV protection than conventional sun creams
What are the dangers of nanomaterials
Long term affects on the body have not been well researched
When used in suncream nanoparticles are absorbed through the skin
what does a dot and cross diagram show
How electrons are transferred
It does not show the 3D of an ionic compound or that it is a giant compound
What does the 2D ball and stick model of ionic bonding show
The electrostatic forces that happen between oppositely charged ions in an ionic compound
But it does not show the 3D structure of an ionic compound
What does the 3D ball and stick model of ionic bonding show
The 3D structure of the ionic lattice and how different ions interact with other ions in all directions to create an ionic lattice
Describe the particles in a solid
They vibrate around a fixed position
Strong force of attraction between each particle
Very close together
Describe the particles in a liquid
Close together but can move in any direction
Wont keep a fixed shape like solids do
Describe the particles in a gas
Particles are very far apart
Move randomly in all directions
Often collide with each other
