Bonding, Structure and Properties of Matter Flashcards
What is an ion?
Ions are charged particles that have lost or gained an electron
What groups are most likely to form ions on the periodic table?
Group: 1,2,6,7
When forming an ion what process does a metal go through (group 1 and 2 elements)?
Oxidation the metals lose electrons
When forming an ion what process does group 6 and 7 elements go through?
Reduction the elements gain electrons
Define ionic bonding?
When a metal loses electrons to form a positively charged ion and a non-metal gains these electrons to form a negative ion. The oppositely charged ions are strongly attracted through electrostatic forces.
What is the diagram we use to show ionic bonds?
Dot and cross diagram
What is the structure of an ionic compound?
Giant Ionic Lattice-with closely packed regular lattice arrangement with strong electrostatic forces between each oppositely charged ions in all directions.
What properties do all ionic compounds have in common?
- High MP and BP due to the strong bonds
- No free flowing electrons so they don’t conduct electricity
What is a covalent bond?
When non-metal atoms bond together by sharing electrons. Each covalent bond provides one shared electron until both atoms have a full outer shell.
What makes covalent bonds strong?
The positively charged nuclei are attracted to the shared pair of the electrons by electrostatic forces.
What diagram do you use to display a covalent bond?
You can use a dot and cross diagram where the outer shells merge and the dots of one element merge with the crosses of the other to represent the sharing of electrons.
What is a disadvantage of a dot and cross diagram?
It does not show how they are arranged in space.
What is a simple molecular substance?
Small molecules containing weak covalent bonds they are usually gases or liquids at room temperature
What is a polymer?
A polymer is lots of small units linked by strong covalent bonds to form a long molecule. There inter molecular forces are stronger than simple covalent bonds.
What are the properties of a polymer?
- Weaker intermolecular forces than ionic or covalent so it has a relatively low MP and BP
- Generally solid
What are Giant Covalent Structures?
They are macromolecules where all atoms are bonded by strong covalent bonds.
Give some properties of Giant Covalent Structures?
They don’t conduct electricity because they don’t contain any charged particles so they also don’t conduct electricity when molten
Very high MP and BP
Give 3 examples of a Giant Covalent Structure?
Diamond - four carbon bond
Graphite - three carbon bonds (forms layers)
Silicon dioxide - silicon and oxygen
What is an allotrope?
An allotrope is a different structual form of the same element in the same physical state.
Give some properties of diamonds
Doesn’t conduct electricity as there is no free flowing electrons
High melting point due to the strong 4 carbon bond
Give some properties of graphite
It has a three carbon bond which makes sheets of carbon atoms arranged in hexagons
Three out of each carbons four outer electrons are used in bonds so graphite has delocalised electrons meaning it can conduct electricity and thermal energy
Graphite is soft and slippery - ideal for lubricants
What do we call a single graphite layer?
Graphene and it is very light
What are fullerenes?
Fullerenes are molecules of carbon, shaped like closed tubes or hollow balls
The carbon bonds can be arranged as hexagons, pentagons and heptagons
What are the uses of a fullerene?
Becasue they can be used to trap a molecule inside its enclosed structure like a “cage” it can be used to deliver certain drugs into the body.
They can be used as industrial catalysts because of their huge surface area catalyst molecules can be attached to the fullerenes
They can also be used as lubricants
