C3 Structure And Bonding Flashcards
What are the 3 states of matter and their state symbols?
Solid(s), liquid(l), gas(g)
What happens when 2 oppositely charged ions approach each other?
They attract
What charge will a group 1 metal have ?
A 1+ charge
What charge will a group 2 metal have?
A 2+ charge
What charge will a group 6 non-metal have?
A 2-
What charge will a group 7 non-metal have?
A 1- charge
What structure do ionic bonds have?
Giant ionic lattices
What do ionic compounds do in water?
They dissolve
Describe the melting points of ionic compounds.
They have high melting points.
When can ionic compounds be able to conduct electricity?
When molten or dissolved in water
Why do ionic compounds have a high melting point?
This is because it takes a lot of energy to overcome the strong electrostatic. force between the ions
Why can ionic compounds not conduct electricity when solid?
Because there are no delocalised electrons that can carry charges.
Why can ionic compounds conduct electricity when molten or in solution?
When an ionic substance is dissolved in solution or molten the ionic lattice is broken down allowing the ions to move freely which allows them to carry charges.
Which elements does ionic bonding happen to ?
A non-metal and a metal
Describe a covalent bond.
A covalent bond is where 2 or more non-metals bond together and share their electrons
In terms of electronic structure how does a covalent bond form?
It is formed by a shared pair of electrons between 2 or more non-metals.
Describe a double bond in a diatomic molecule.
In diatomic oxygen the oxygen atoms each have 6 valence electrons and by sharing 2 pairs of electrons with the other oxygen this forms a double bond.
How are the properties of a double bond different than the properties of a single covalent bond?
A double bond has a higher melting and boiling point
Describe the melting and boiling point of small molecules.
The melting and boiling points are low
Why do small molecules not conduct electricity?
Because there are no delocalised electrons
What are intermolecular forces?
These are the attractive and repulsive forces that occur between molecules.
How does the size of molecules affect melting and boiling points?
Larger molecules generally have higher melting and boiling points compared to smaller molecules.
Why can small molecules not be able to conduct electricity?
Their electrons are in covalent bonds so there are no delocalised electrons.
What substances would have weak intermolecular forces?
Molecular substances
What is an advantage of using a two-dimensional space-filling model?
It clearly shows the arrangement of ions in one layer of the lattice.
What is a limitation of using a two-dimensional space-filling model?
It doesn’t show how the next layer of ions is arranged.
What is an advantage of using a 3-dimensional ball and stick model?
It shows the direction of forces between the ions.
What are two limitations of using a 3-dimensional ball and stick model?
-It shows lots of free space between the ions.
- It uses sticks to show the forces between the ions.
What are the main physical properties of diamond and graphite?
Diamond is the hardest known natural substance, has a very high melting point and does not conduct electricity.
Graphite is soft, it has a high melting and boiling point and it conducts electricity.
Describe the melting and boiling points of giant covalent structures.
They have high melting and boiling points.
Explain the properties of diamonds in terms of bonding.
Diamond is very strong and does not conduct electricity as it has 4 covalent bonds so there are no delocalised electrons.
What can graphite be used for based on its properties?
Lubricants and circuits
Describe the structure of graphite in terms of carbon atoms.
Graphite is built of hexagonal layers of carbon atoms that have 3 covalent bonds so there are delocalised electrons between the sheets.
Explain the properties of graphite in terms of bonding.
As graphite is built up of carbon atoms with 3 covalent bonds, this means that there are delocalised electrons between the sheets of carbon.
What can diamond be used for based of its properties?
Diamond drill bits
Describe the relationship between graphite and graphene.
Graphene is a single layer of graphite
Describe and explain the applications of fullerenes.
Fullerenes are used in medicine as cages to put drugs in and then they are transported to a certain location within the body.
What are the main physical properties of fullerenes?
-hollow
-cage-like structures.
Explain the structure of fullerenes.
Their structures are based on hexagonal rings of carbon atoms joined by covalent bonds.
What is the molecular formula of buckminsterfullerene?
C60
What are the properties of fullerenes and carbon nanotubes?
-high tensile strength
-high electrical conductivity
-high ductility
-high heat conductivity
What are the uses of fullerenes and carbon nanotubes?
Fullerene molecules can be used for drug delivery into the body, as lubricants, as catalysts and in the form of carbon nanotubes can be used for reinforcing composite materials
What structure do metals form?
A giant structure
Describe metallic bonding.
Metal ions are surrounded by a sea of electrons.
Explain how metal atoms form giant structures.
The metal atoms lose their valence electrons which become delocalised and the metal atoms become positively charged ions. So the metal ions are surrounded by a sea of electrons.
List the physical properties of metal.
- Maleable
- Ductile
- Sonorous
- Lustrous
Describe the structure of a pure metal.
The metal ions are arranged in a lattice
Describe why metals are alloyed?
Metals are alloyed in order to make them stronger as the extra element(s) disrupt the lattice.
Justify why alloys are more often used than pure metals.
Alloys are more often used because they are stronger than pure metals.
How does alloying affect the structure and bonding in metals?
Alloying disrupts the lattice structure of metals and makes it harder for the metal atoms to slide over each other.
State a definition of nanoscience.
This is the study of matter at the nanoscale.
Describe the size of nanoparticles.
Nano particles are extremely small - 1x10^-9 m
What are coarse particles known as?
Dust
How small are course particles?
2.5x10^-6m
How small are fine particles?
1x10^-7
Describe how surface area to volume ratio increases as particle size decreases.
A greater proportion of the particles are available on the surface for collisions
How does surface are to volume ratio affect its affects on properties?
Increased surface area to volume ratio allows for an increased rate of reaction as more surface is available.
What can titanium dioxide nanoparticles be used for and why?
They can be used for sunscreen as they have the property of reflecting UV light.
What are the disadvantages of using nanoparticles?
Nanoparticles are fairly new so we don’t know the long term causes of using them. Also as they are so small they could potentially enter living organisms or pass through our skin into the bloodstream.
List uses of nanoparticles.
- Sunscreen
- Anti - bacterial coatings
- Cleaning surgical equipment
- electrical circuits
Why can nanoparticles have new applications?
Nanoparticles can have new applications as they are fairly new and we haven’t discovered all their uses.
Why should nanotechnology research continue?
It should continue because nanotechnology might be able to save lives in medicine.
What is a monatomic ion?
A charged particle that consists of one particle
Explain how a Group 1 metal would react with a Group 7 non-metal.
The Group 1 metal would transfer its valence electron to the Group 7 non-metal. The Group 1 metal becomes positively charged and the Group 7 non-metal becomes negatively charged. As they are opposite poles the metal and non-metal are electrostatically attracted.
