Later C3 Flashcards
Name the groups and what charge of ions they make from ionic bonding
1: +1
2: +2
3: +3
4: +4, -4
5: -3
6: -2
7: -1
0: ❌
What is ionic bonding
Ionic compounds are held together by strong forces of attraction between their oppositely charged ions
If you had: Al3+ and O2- what charge would you need for them to become neutral
(Al3+)2, (O2-)3 ( they both equal the same number of opposite charge, 6 is their LCM )
6+ and 6-
What would happen in order for potassium ( K ) and oxygen (O) to correctly ionicly bond
Oxyegn needs 2 more electrons for a full outer shell. K has one on outer shell. x2 K to lose 1 electron each ( stable now ) to give to O which now has 8 on outer shell ( stable )
Why can sea water conduct electricity
Sea water has salt in it and therefore the ions are free and separated so they are drawn to opposite charge and can carry a charge, therefore they can conduct electricity
Why do ionic compounds have high melting points
It takes a lot of energy to break up every bond in the lattice since there are a lot of bonds to break and you have to overcome the electrostatic attraction and therefore you need immense heat to melt them
Give the properties of an ionic solid
Ions are in fixed position in a giant lattice. They vibrate but cannot move around. It does not conduct electricty
Give properties of molten ionic compound
High temperature provides enough energy to overcome the many strong attractive forces between ions. Ions are free to move around within the molten compound. It does conduct electricty
Properties of ionic compound in solution
Water molecules separate ions from the lattice. Ions are free to move around within the solution. It does conduct electricty
What are the difference between inter and intra molecular forces
Intermolecular forces: between molecules ( drawn as dotted lines )
Intramolecular forces: within the molecules ( drawn as lines )
Describe what would happen if 2 hydrogen atoms covalently bonded
The two molecules would share electrons so that they each have 2 on the outer shell ( full and stable )
Describe how a carbon atom would bond with two oxygen atoms
The carbon atom would share two of it’s 4 electrons with each of the oxygen atoms ( 2 each ) each of the oxygen atoms would also share their two electrons with carbon and have 4 spare. This means that each atoms has 8 electrons on the outer shell
Which noble gas electron structure do the atoms in a molecule of hydrogen chloride attain?
Hydrogen would have 2 on outer shell: same as helium
Chlorine would be 2,8,8: same as Argon
How do the covalent bonds bond the atoms to each other
The electro static attraction between the electrons and the positive nuclei on either side of the pair of electrons holds the atoms together
What happens to the INTERmolecular forces when the INTRAmolecular forces are stronger
The intermolecular forces are weaker
What happens to the INTERmolecular forces when the INTRAmolecular forces are weaker
The intermolecular forces are stronger
What are the melting and boiling points of substances made of simple molcules
Both are lower
Why do substances made of simple molecules have lower melting and boiling points
The forces between the molecules ( intermolecular ) are weak so they need little energy to melt or boil
Why can’t molecules carry charge?
They have no overall charge so there is no electrostatic attraction so they can’t carry a charge
Properties of giant covalent structures
Very high melting points
Insoluble in water
Do nkt conduct electricity
What do chemists call different forms of the same element in the same state
Allotropes
Why is graphite soft and slippery
It has covalent bonds horizontally although it has no covalent bonds connecting the layers so the layers can slide between one another
Why is diamond so rigid
It is a gaint covalent structure making is very strong since the carbon bonded in all directions ( carbon atoms have each made 4 bonds )
Why can graphite conduct electricity and thermal electricity
Every carbon has one electrons spare ( called delocalised electrons ) can move between the layers and carry a charge
What medical use can fullerene cages provide
Delivering toxic drugs to cancerous cells to only kill off and damage the cancer cell amd not the rest of the cell
What are bucky balls made out of
Hexagons of carbon
What is graphene
A single layer of graphite and it was found when scientists in 2004 ripped selotape off graphite to get a layer one cell thick ( graphene )
What is graphene usefull for
It is incredible strong for what it is
It is an excellent conductor
What can graphene be used for in the future
It can be used to make more powerful computer chips and flexible electronic displays. Such as watching a film with a screen on your sleeve
What was the first fullerene to be discovered
C60. A fullerene with 60 carbon atoms to make a sphere
How did buckminster fullerene gets its name and what can it be abreviated to
A canadian scientist called Buckminster Fuller and can be abreviated to ‘ bucky ball ‘
Why does the melting and boiling point and also conductivity of metals go up as the groups progress
Because they give as much delocalised electrons to the sea of delocalised electrons as their group number. E.g. group 3: each metal atom will delocalise 3 electrons.
This means that there is stronger electrostatic forces of attraction between the positive metal ions and the nucleus meaning it will take more energy to break them apart
How are the ions arranged in a metallic lattice
In uniform and neatly
Why can a metal be bent, shaped and pulled out into wire?
Because the atoms are arrangd regularly and can slide out over each other easily
What is it called when a metal can be hammered into shape
Malleable
What is it called when a metal can be pulled out into wires?
Ductile
Why can alloying a metal make it harder
The different atoms in a metal can distort the uniform arrangement of the original metal so that the atoms cannot slide over one another as easily
Why are metals good conductors of heat and electricity
The delocalised electrons can flow through the giant metallic lattice. The electrical charge and thermal energy transferred quickly through metal by the free - moving electrons
What is an alloy
A mixture of two or more elements, at least one of which has to be a metal
What is nanoscience
The study if small particles between 1 and 10 nanometres in size
Why do materials behave differently when they are under 100nm in size?
Nanoparticles have a huge proportion of their molecules at the surface of the particle compared with a grain of sand
What is the rule with surface area : volume ratio?
As a cube’s side decreases by 10 the SA : V ratio increases by 10
Show how the SA : V rule works
Cube of 100cm sides: Surface Area = ( 100 x 100 ) x 6 ( cubes have 6 equal sides where you need to find area V = (100 x 100x 100)cm3 = 1,000,000 cm3 SA : V ratio = 60,000cm2 : 1,000,000cm3 = 0.06 / cm WHEREAS Cube of 10cm sides SA: ( 10 x 10 ) x6 = 600 V = ( 10 x 10 x 10 )cm3 = 1000cm3 SA : V ratio = 600cm2 : 1000cm3 = 0.6 / cm
What does a high surface area : volume ratio give
They are highly reactive compared to other reactants
What is better about using nanoparticles than other materials?
It means that the use of nanoparticles instead of traditional bulk materials should mean that smaller quantities are needed. Their high SA : V ratio means they are much more reactive than materials with normal particles sizes
What does the use of nanoparticles mean for the future? 🚀🤷🏻
It will result in a more sustainable approach in industry as less resources are used up
What is the length of 1 nanometre in metres
1 x 10^-9 metres or 0.0000000001 ( a billionth of a metre )
What are delocalised electrons
Electrons that have not been used in bonding
Where are the delocalised electrons in metallic bonding
In the sea of electrons
Uses of nanoparticles
Silver nanoparticles to act as anti microbial surfaces for hospitals and keyboards
Titanium nanoparticles on windows to break down dirt through chemical resctions with sunlight
Structure of graphite
Carbon atoms are bonded to three other ones. They form hexagons why are arranged in giant layers. There are only weak intermolecular forces attaching these layers vertically.
Metallic bonding
Metals are a giant lattice of positively charged ions. The outer electrons can easily move around the giant structure in a sea of ions. Strong electrostatic attraction between the negatively charge electrons and positively charged ions bond the meatals ions together.
