Topic 2-Bonding Flashcards
What is metallic bonding and describe features of metals?
Electrostatic attraction between positive ions and a sea of delocalised electrons.
Metals are malleable and ductile
What does the strength of metallic bonding depend on and the effect on melting and boiling point?
Metallic bonds depend upon the amount of protons
The more protons the stronger the metallic bond as greater nuclear charge pulls in valence electrons
This increases boiling and melting point as more energy required to overcome metallic bonds
What is Ionic bonding and explain some properties?
Bond between positive and negative ions held together by electrostatic forces of attraction
Involves transfer of electrons
High Melting point
Soluble in water as they are charged
Does not conduct electricity in solids
Cannot be shaped
Brittle-As repulsion between same charged ions are strong
What is covalent bonding?
Electrostatic attraction between positive nucleus and negative electrons
It forms between 2 non metals
Involves sharing of electrons
What evidence is there for the existence of ions?
Migration of ions on wet filter paper-electrolysis of copper chromate
Electron Density Maps
Why does Ionic bonding have high melting and boiling points?
Strong electrostatic forces of attraction between oppositely charged ions so more energy is required to break forces
Why can Ionic compounds conduct electricity in solution but not in solids?
In solutions,ions are free to move and carry charge so it can conduct electricity
In solids,ions cannot move
Explain the properties of Diamonds?
High Melting Point- as it has strong covalent binds so lots of energy is required to overcome these bonds
High strength as each carbon is joined to 4 others so has a coordination no. of 4,strong delocalised electrons
Cannot conduct electricity
Explain the bonding,structure and properties of graphite?
High Melting Point-Has lots of strong covalent bonds so lots of energy required to break bonds
Each Carbon bonded to 3 others
High Strength- Low strength as it has weak intermolecular forces of attraction so layers can slide over each other
Can conduct electricity as it has delocalised electrons
How does Ionic charges and Ionic Radii affect Ionic bonding?
The Greater the charge of the ion,the stronger the Ionic bond and so a higher melting and boiling point
The smaller the Ionic radii the greater the Ionic bonding as electrostatic attraction is greater when Ionic radii is small so it is stronger and has a higher melting and boiling point
Explain how Ionic radius changes down the group?
Ionic Radius increases down the group as atomic number is greater so there is more electron shell
