Chemistry: Graphene, Fullerenes, Metallic Bonding, Alloys, and Compounds

Comprehensive review flashcards covering Graphene, Graphite, Fullerenes, Metallic Bonding, Alloys, Ionic Compounds, and Covalent Small Molecules based on lecture notes.

What is graphene?

Graphene is a single, atom-thick layer of carbon atoms arranged in a flat, hexagonal honeycomb-like lattice.

Where is the carbon-based material for graphene naturally found in daily items?

It is found in pencil leads as graphite, which consists of layers of graphene.

In what year and in what city was graphene first isolated?

Graphene was isolated in $2003$ in Manchester.

How was graphene isolated from graphite in $2003$?

It was isolated by shearing layers off graphite using sellotape.

How does the strength of graphene compare to steel?

Graphene is $200\text{x}$ stronger than steel.

How thin is graphene compared to a piece of paper?

Graphene is a million times thinner than a piece of paper.

Why is graphene stronger than diamond and $200\text{x}$ stronger than steel?

Due to its strong carbon-carbon bonds.

How thick is a single layer of graphene?

It is an atom-thick layer (only one atom thick).

What percentage of visible light passes through graphene?

Almost $98\%$ of visible light passes through graphene.

Why is graphene transparent?

Because it is only one atom thick, allowing almost $98\%$ of visible light to pass through.

How does graphene compare to copper in terms of heat and electrical conductivity?

Graphene conducts heat and electricity better than copper.

What is the structural relationship between graphite and graphene?

Graphite is made of layers of graphene.

What flexibility property is associated with graphene?

Graphene is a flexible material.

What potential application does graphene have in display devices?

Touch screens in devices.

What potential application does graphene have in water treatment?

Water filtration systems.

What potential medical applications exist for graphene?

Medical sensors and drug delivery.

What energy-related applications are potential uses for graphene?

Energy storage and composites.

Why does graphene have a reputation as a 'wonder material'?

Its reputation stems from its superlative properties: being an atom-thick, million times thinner than paper, stronger than diamond, $200\text{x}$ stronger than steel, transparent, flexible, and conducting heat and electricity better than copper.

What date is listed on the Graphene and Fullerenes note page?

Monday 21st September 2026.

How many electrons are in the outer shell of carbon according to the Do Now section?

$4$ electrons.

How many covalent bonds does each carbon atom form in graphite?

$3$ covalent bonds in each carbon atom.

Why is a lot of energy needed to break structures like graphite?

Because many covalent bonds need to be broken.

How is graphene defined in the Monday 21st September 2026 notes?

Graphene is a single layer of graphite.

What are fullerenes?

Fullerenes are molecules of carbon with hollow shapes.

What are carbon nanotubes?

Carbon nanotubes are cylindrical fullerenes with a high length to diameter ratio.

What is the definition of an alloy?

Alloys are metals that are not pure.

Why are alloys harder than most pure metals?

Because the layers are distorted and cannot slide over each other.

Why do metals generally have very high melting and boiling points?

Because there are strong electrostatic forces of attraction between positive ions and delocalized electrons.

Why is a pure metal better suited than an alloy for a luxury decorated plaque?

Pure metal, because it is valuable.

Why is an alloy better suited than a pure metal for a structural iron girder?

Alloy, because for building you would want the girder to support weight.

Why is an alloy better suited than a pure metal for a copper coin?

Alloy, so the coin would not bend easily.

Why is pure metal better suited than an alloy for copper wire inside an electrical device?

Pure metal, so it can bend easily to fix easily and conduct.

Why is an alloy better suited than pure metal for an aluminium bike frame?

Alloy, because it needs to support weight so it would not break easily.

What date is shown at the top of the Metallic Bonding note page?

Tues 22nd September 2026.

What measurement value is written next to the ion diagram on the Metallic Bonding page?

$0.2\,\text{nm}$.

What ion charge label is shown in the Metallic Bonding diagram?

$3+$ (or $A^{3+}$).

How does polymer chain length affect its melting point?

The melting point increases as the length of a polymer increases until it has reached its peak melting point.

What are the five general properties of metals listed in the notes?

Good conductor, flexible, ductile, sonorous, malleable.

Describe the structural arrangement of particles in a metal.

Layers of positive ions surrounded by a sea of delocalised electrons that can carry charge through the structure.

Why do metals have high melting points according to the Metallic Bonding notes?

As there are strong electrostatic forces of attraction between positive ions and delocalized electrons.

Why are pure metals soft and malleable?

Because pure metal atoms are arranged in layers that can slide over each other.

Why are alloys hard compared to pure metals?

Because in alloys, the layers are distorted and cannot slide over each other.

What particle feature in metallic bonding carries charge through the structure?

A sea of delocalised electrons.

Does $CuCl_2$ dissolve in water, conduct electricity in solution, and what is its melting point?

Dissolves: Dissolved; Conducts in Solution: Yes; Melting Point: High.

What classification of compound is $CuCl_2$?

Ionic compound.

Does $CuSO_4$ dissolve, conduct in solution, and what is its relative melting point?

Dissolves: Dissolved; Conducts in Solution: Yes; Melting Point: High.

What are the solubility, solution conductivity, and melting point properties of $NaCl$?

Dissolves: Dissolved; Conducts in Solution: Yes; Melting Point: High.

What are the dissolution, conductivity, and melting point properties of $KCl$?

Dissolves: Dissolved; Conducts in Solution: Yes; Melting Point: High.

What are the dissolution, conductivity, and melting point properties of $BaCl_2$?

Dissolves: Dissolved; Conducts in Solution: Yes; Melting Point: High.

Why do ionic compounds conduct electricity when dissolved in solution?

As they have ions that can move.

Why do ionic compounds have high melting points?

As they have strong electrostatic forces of attraction in all directions so a lot of energy is needed to break them.

What type of bonding involves two oppositely charged particles?

Ionic bonding.

Why do small covalent molecules have low melting points?

Because they have weak intermolecular forces, so very little energy is needed to break them.

What chemical formula is given for water in the small covalent molecules section?

$H_2O$.

What chemical formula is given for ammonia in the small covalent molecules section?

$NH_3$.

What chemical formula is given for methane in the small covalent molecules section?

$CH_4$.

What date is shown on the experimental table page for Covalent Molecules?

Monday 14th September 2020.

What are the colour, solubility, conductivity in solution, and melting point of sugar?

Colour: white; Dissolves: Yes; Conducts in Solution: No; Melting Point: Low.

What are the colour, solubility, conductivity in solution, and melting point of stearic acid?

Colour: white; Dissolves: No; Conducts in Solution: No; Melting Point: Low.

What are the colour, solubility, conductivity in solution, and melting point of wax?

Colour: white; Dissolves: No; Conducts in Solution: No; Melting Point: Low.

Why are sugar, stearic acid, and wax categorized as small covalent molecules in the test table?

Because they have low melting points and do not conduct electricity in solution.

In what directions do electrostatic forces of attraction act in ionic compounds?

In all directions.

Why can pure copper wire bend easily?

Because it is a pure metal whose layers of positive ions can slide over each other.

Why is graphite able to be sheared into graphene using sellotape?

Because graphite is composed of individual layers of graphene.

What thermal conductivity property does graphene have?

High thermal conductivity (it conducts heat better than copper).

What electrical conductivity property does graphene have?

High electrical conductivity (it conducts electricity better than copper).

What is the full name of the carbon structure that consists of single-atom-thick hexagonal layers?

Graphene.

What structural ratio characterizes carbon nanotubes?

A high length to diameter ratio.

How do pure metals differ from alloys in terms of structural layer distortion?

Pure metals have ordered layers that slide over each other, whereas alloys have distorted layers that cannot slide.

What causes pure copper to be a good conductor inside an electrical device?

Its delocalised electrons that can carry charge through the metal structure.

Why does an iron girder in a building need to be made of an alloy?

To support weight effectively, as the distorted layers prevent sliding and make it hard.

Why does a copper coin need to be made of an alloy?

So the coin will not bend easily when handled.

Why does an aluminium bike frame need to be made of an alloy?

To support weight so it will not break easily.

What amount of energy is required to break ionic bonds in ionic compounds?

A lot of energy is needed to break them because of strong electrostatic forces of attraction in all directions.

What amount of energy is required to overcome forces in small covalent molecules?

Very little energy is needed because they have weak intermolecular forces.

What happens to polymer melting point as polymer length increases?

It increases until it reaches its peak melting point.

Which compound listed in the ionic table contains barium?

$BaCl_2$ (Barium chloride).

Which compound listed in the ionic table contains potassium?

$KCl$ (Potassium chloride).

What are the two copper compounds listed in the ionic compounds table?

$CuCl_2$ and $CuSO_4$.

What sound property is listed under the properties of metals?

Sonorous.