Unit 2- Bonding, Structure and properties of matter Flashcards
Bonding between non-metal and metal
Ionic
Bonding between non-metals
Covalent
Bonding in metals
Metallic
Why do ionic bonds have high boiling point
Strong electrostatic attraction
between oppositely charged ions
Takes a lot of energy to separate
Define ionic bond
Strong electrostatic attraction
between positive metal ions and negative non-metal ions
Structure of ionic substances
Giant lattice
Metallic bond
Electrostatic attraction
Positive metal ions and sea of delocalised electrons
Why do metals have high boiling points?
Strong electrostatic attraction
Positive metal ions and sea of delocalised (free) electrons
Takes a lot of energy to seperate
Covalent bond
Shared pair of electrons
Between non-metals
Why do simple covalent bonds have low boiling points?
Weak inter molecular forces
Takes little energy to separate molecules
Giant Covalent examples
Diamond
Graphite
Silicon Dioxide
Why do giant covalent substances have high boiling points
Strong covalent bond
Lots of energy need to break it up
Why do metals conduct electricity?
Sea of delocalised electrons
Carry electrical charge
Throughout the metal
Define alloy
Mixture of a metal and at least one other element
Why are alloys harder than metals
Different Size particles
in distorted arrangement
Hard to slide over each other
Why are pure metal softs
In nice neat rows
layers slide off easily
Why do metals conduct thermal energy?
Delocalised electrons
Carry energy throughout the solid
What are diamonds made of?
Carbon
Why are diamonds hard?
Each carbon attached to 4 other
Strong covalent bond
Why is graphite soft?
Layers of carbon
Can slide over each other
Why does graphite conduct electricity?
Each carbon has spare electron
delocalised (free) electron can carry electrical charge throughout
What is graphene?
One layer of graphite
Why are nano particles useful?
high size to charge ratio
Define Nanoparticle
1-100nm in size
made up of only a few hundred atoms
Uses of nano-particles
Sun Cream
Deodorants
Catalysts
