Bonding, Structure And Properties Of Matter Flashcards
(19 cards)
What are the three types of bonding
Ionic
Covalent
Metallic
When does ionic bonding occur (2 points)
When a metal and non metal react, the metal loses one electrons to form a positively charged ion and the non metal gains these to form a negatively charged ion
These oppositely charged ions are strongly attracted by the electrostatic forces
What is the structure of an ionic compound (2 points)
Giant ionic lattice
The ions form a closely packed regular lattice arrangement and there are very strong electrostatic forces of attraction between oppositely charged ions
Properties of ionic compounds (2)
High melting and boiling points due to many strong bonds which take lots of energy to overcome
Can conduct electricity when melted/ molten as the ions are free to move and carry an electric charge
When do covalent bonds occur
When two non metal atoms bond together and share pairs of electrons
Why doesn’t N2 conduct electricity
Because molecular compounds do not have a charge and there are no free electrons to roam
What is a polymer
Lots of small chains to form a long molecule with repeating sections joined by strong covalent bonds
What is the structure of diamond
Giant covalent structure made of carbon atoms that each form 4 covalent bonds
Properties of diamond (3)
Hard
High melting point because of the strong covalent bonds which require lots of energy to overcome
Doesn’t conduct electricity because there are no free electrons or ions
Structure of graphite
Three covalent bonds creating sheets of carbon arranged in hexagons
Properties of graphite (3)
Can be used as a lubricating material (no covalent bonds between layers, held together weekly so they are free to move over each other)
High melting point because the covalent bonds need lots of energy to overcome them
Conducts electricity and thermal energy (each carbon atom has one delocalised electron which is free to move)
What is one layer of graphite called
Graphene
Structure of graphene
One sheet of carbon atoms joined together in hexagons
One atom thick
Properties of graphene (3)
Very strong because of the covalent bonds
Light
Can conduct electricity
What is an allotrope
Different structural forms of the same element
Structure of fullerenes
Molecules of carbon shaped like hollow balls or closed tubes
Uses of fullerenes (3)
Can be used in electronics or to strengthen materials
Have a huge surface area so can be used as catalysts in industry
Lubricants
Properties of compounds with metallic bonds
High melting and boiling points as there are strong electrostatic forces that need a lot of energy to be broken
Solid at room temp
Good conductors of electricity and heat because of the delocalised electrons that carry charges
Malleable - layers of atoms can slide over each other
Why are alloys harder than pure metals
Different elements have different sized atoms so when another element is mixed with a pure metal, the new metal distorts the layers of the metal atom, making it more difficult for them to slide over each other
