C3 Structure And Bonding Flashcards
What is ionic bonding
Ionic compounds are held together by strong forces of attraction between their oppositely charged ions
How are electrons transferred between a magnesium atom and oxygen atom
The magnesium atom has 2 electrons on its outermost shell which it wants to lose but oxygen has 6 and wants to gain 2 so the magnesium’s electrons go to the oxygen atom
What ions do group 1 form
1+
What ions do group 2 form
2+
What ions do group 3 form
3+
What ions do group 4 form
Do not form ions
What ions do group 5 form
3-
What ions do group 6 form
2-
What ions do group 7 form
1-
What ions do group 0 form
Never form ions in compounds
Why do ionic compounds have high melting points
The ionic bonds are very strong and operate in all directions which hold a giant ionic lattice together meaning it takes a lot of energy to break them
What are ionic compounds at room temperature
Solids
When and why will ionic compounds conduct electricity
When molten or dissolved in water. This is because their ions can then become mobile and can carry charge through the liquid
Why are convalent bonds formed
Atoms of non-metals share pairs of electrons with each other
Why do atoms convalently bond with other atoms
To gain more stability, which is gained by forming a full electron shell
How do the pairs of electrons in convalent bonding bond the atoms together
Electrostatic attraction between electrons and positive nuclei on either side of the pair of electrons
Why do convalent compounds have low boiling and melting points
They have strong convalent bonds yet the intermolecular forces between molecules are weak therefore meaning it doesn’t require much energy to seperate.
Do simple molecules conduct electricity
No as they have no overall charge meaning they cannot carry electrical charge.
What are polymers
A substance or material which are made up of many small reactive molecules that bond to each other to form long chains
Properties of giant convalent structures
-They have very high melting and boiling points.
-They are insoluble in water
-Apart from graphite, they are hard and don’t conduct electricity.
What are giant convalent structures
Huge networks of atoms held together by convalent bonds
Why can graphite conduct electricity
Graphite’s layers are arranged in hexagons, each carbon atom forms three strong convalent bonds. Carbon atoms have 4 electrons in the outer shell meaning there is one spare on each atom in graphite. These delocalised electrons move freely across the layers and allow graphite to conduct electricity
Why is graphite used for pencils
As there are no convalent bonds between the layers only weak intermolecular forces the layers can slide over each other easily which can transfer on to paper.
What are fullerenes
Large cage like structures and tubes, based on hexagonal rings of carbon atoms
What are fullerenes used for
A transport mechanism for drugs to specific sites in the body
Difference between graphene and graphite
Graphene is a single layer of graphite so it is one atom think
Properties of graphene
-excellent electrical conductivity
-incredibly strong for there mass
-very low density
How are metal atoms structured
Closely packed together and arranged in regular layers.
What is metallic bonding
The electrostatic attraction between positive metal ions and delocalised electrons
What is an alloy
A mixture of metals
