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What type of bonding occurs between oppositely charged ions?
Ionic bonding
What type of bonding occurs between atoms which share pairs of electrons?
Covalent bonding
Which type of bonding is found in atoms which share delocalised electrons?
Metallic bonding
Which type of bonding occurs in compounds formed from metals combined with non-metals?
Ionic bonding
Which type of bonding occurs in most non-metallic elements?
Covalent bonding
Which type of bonding occurs in compounds of non-metals?
Covalent bonding
Which type of bonding occurs in alloys?
Metallic bonding
What is transferred in ionic bonding?
Electrons
When a metal atom becomes positively charged what has it lost?
Electrons
What would be the charge of an ion formed from a Group 1 element?
+1
What would be the charge of an ion formed from a Group 2 element?
+2
What would be the charge of an ion formed from a Group 6 element?
2-
What would be the charge of an ion formed from a Group 7 element?
-1
What is an ionic compound?
A giant structure of ions
What holds ionic compounds together?
Strong electrostatic forces of attraction between oppositely charged ions
Name 2 covalently bonded substances with giant covalent structure
Diamond, Silicon dioxide
Some covalently bonded substances have very large molecules, such as
Polymers
How are the atoms arranged in metals?
In a regular pattern
What are the electrons in the outer shell of metal atoms like?
Delocalised
What does delocalised electrons mean?
Electrons that are free to move around
What are the three states of matter?
Solid, Liquid and Gas
What takes place at the melting point?
Melting and Freezing
What takes place at the boiling point?
Boiling and Condensing
How does the strength of the forces between particles affect the boiling point?
The stronger the forces between the particles the higher the boiling point
What are the limitations of the particle model?
There are no forces All particles are represented as spheres The spheres are solid
What is the state symbol for a solid?
(s)
What does the symbol (g) mean?
Gas
What does the symbol (aq) mean?
Aqueous
Why do ionic compounds have high melting and boiling points?
Due to the large amounts of energy needed to break the many strong bonds
Why can ionic compounds conduct electricity when melted or dissolved in water?
Because the ions are free to move and so charge can flow
Substances that consist of small molecules are usually
Gases or Liquids
When a substance melts which forces are overcome?
Intermolecular forces
Why do small molecules not conduct electricity?
Because the molecules do not have an overall electric charge
Which are stronger; covalent bonds or intermolecular forces?
Covalent bonds
How are the atoms in polymer molecules linked?
By covalent bonds
Polymers are usually which state at room temperature?
Solids
In pure metals how are the atoms arranged?
In layers
Why are metals often mixed with other metals to make alloys?
To make metals harder as pure metals are too soft for many uses
Why do metals have high melting and boiling points?
Because they have strong metallic bonding
Why are metals good conductors of electricity?
Because they have delocalised electrons to carry electrical charge
Why are metals good conductors of thermal energy?
Because energy is transferred by the delocalised electrons
In diamond how many bonds does each carbon atom form?
4
Why does diamond have a very high melting point?
Lots of strong covalent bonds
In graphite how many bonds does each carbon atom form?
3
In graphite, one electron from each carbon atom is
Delocalised
What are the shapes of the rings in graphite?
Hexagonal rings
What is graphene?
A single layer of graphite
What are fullerenes?
Molecules of carbon atoms with hollow shapes
What was the first fullerene to be discovered?
Buckminsterfullerene
What shape does buckminsterfullerene have?
Spherical
How many carbon atoms are there in buckminsterfullerene?
60
What are carbon nanotubes?
Cylindrical fullerenes
What is the ratio of the length to diameter of carbon nanotubes like?
High
What are carbon nanotubes useful for?
Nanotechnology, Electronics and Materials
What size would nanoscience be referred to as?
1-100nm
What diameters do fine particles have?
100 and 2500 nm (1 x 10-7 m and 2.5 x 10-6 m)
What diameters do coarse particles have?
1 x 10-5 m and 2.5 x 10-6 m
What can coarse particles be referred to as?
Dust
If the side of a cube decreases by a factor of 10, what will happen to the surface area to volume ratio?
Increase by a factor of 10
What can nanoparticles be used for?
medical treatments cosmetics, deodorants sunscreens electronics catalysts
What results in the different properties?
Tiny size Large surface area to volume ratio
What are the concerns of the use of nanoparticles?
small size of nanoparticles makes it possible to breathe them in, or for them to pass into cells and cause harm Unknown long term risks
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