C2 New Version Flashcards
Why do metal have high melting point
Because lots of heat energy is needed to overcome strong electrostatic attraction between many positive ions and negative electrons
Why do non metals have a low melting point
It does not take a lot of heat to overcome the weak attraction
What is metallic bonding
A strong electrostatic attraction between positive ions and negative delocalised electrons
Ionic bonding
A non metals and metals loses or gains electrons to obtain a full outer shell
Covalent
When two or more non metals share electrons to obtain a full outer shell
Metals are malleable
Because the layers of ions can slide past
Metals are good conductors
Because free elections carry charge
Alloys are harder
Because different sizes makes the layers distorted and Cannot slide past each other
Alloys have high melting points because
Lots of energy is needed to overcome the strong electrostatic attraction between the positive ions and negative electrons
Alloys are good conductors
Because free elections can move and carry charge
Ionic compound have a high melting point
Because lots of energy is needed to overcome the strong electrostatic attraction between the positive ions and negative ions
Describe ionic bond
Electron transfers from metal to non metal to have full outer shell
Why do small covalent structures have a low boiling point
Little bit energy is needed to overcome weak intermolecular forces
Why are Small covalent properties soft
Weak intermolecular forces
Why do small covalent particles have poor electrical conductors
Because molecules are neutral
Why do diamonds have high melting boiling points
Needs lots of energy to overcome strong covalent
Why are diamonds very hard
Giant structure of strong covalent bonds so layers cannot slide
Why do diamonds not conduct electricity
No delocalised electrons the Carry charge
Why do diamonds have a crystal structure
4 covalent bonds to each atom in tetrahedral structure
Why does graphite have a high melting and a boiling point
Needs a lot of energy to overcome strong covalent bonds
Why is graphite soft
Layers of atoms can slide past each other because of weak intermolecular forces
Why is graphite a good electrical conductor
Because of delocalised electrons can move and carry charge
Why does graphite rub off into paper
3 covalent bonds to each atom in hexagonal layers
Why does silicone have a crystal structure
Covalent bonds in tetrahedral structure
Why does silicone have a high melting and boiling point
Lots of energy needed to overcome strong covalent bonds
Why is silicone very hard
Layers are distorted and can’t slide past each other
Why is silicone a poor conductor
No delocalised elections are free and can carry charge
What are the properties of metal
Malleable/ductile,good conductors
High melting points
What are the properties of alloys
High melting point. Harder. Good conductors
What are the properties of ionic compounds
High melting points Brittle. Do not conduct electricity when solid. Do conduct electricity when liquid
What are the properties of covalent bonds
Lower melting boiling point Soft Poor electrical conductor
What are the properties of diamonds
High melting and boiling points does not conduct electricity hard crystal structures
What are the properties of graphite
Soft high melting and boiling points points good electrical conductor layers will rub of paper
What are the properties of silicon oxide
Crystal structure high melting and boiling point hard poor electrical conductors
