Chemistry- Bonding, Structure and Properties of matter Flashcards
1
Q
What is covalent bonding?
A
- Non metal + non metal
- Electrons are shared
- Covalent bonds can be drawn using dot and cross diagrams
2
Q
What is ionic bonding?
A
- Metal + non metal
- Transfer electrons
- Metal atom loses electrons and non metal gains electrons
- Dot and cross diagrams can show how ionic compounds are formed
3
Q
What are the properties of giant ionic lattices?
A
- Metal + non metal
- Oppositely charged ions attract
- High melting + boiling points —> strong electrostatic attraction - needs lots of energy to overcome
- Conduct electricity as liquid- ions can move
- Can’t conduct as solid- ions can’t move
4
Q
Simple molecular substances
A
- Small number of atoms
- Non metal + non metal
- Low melting + boiling point —> weak intermolecular forces- don’t need much energy to overcome
- Never conducts electricity- no free electrons or ions
5
Q
What is a polymer?
A
- A polymer is a long chain of repeating units. Small units link together to form long molecules.
- All atoms are joined by strong covalent bonds
- Intermolecular forces are weak so have low melting + boiling points
6
Q
What are the 3 giant covalent structures
A
Diamond, graphite, silicon dioxide
7
Q
Properties of giant covalent structures
A
- Very high melting + boiling points - strong covalent bonds- takes lots of energy to overcome
- Don’t conduct electricity- no charged particles
8
Q
Diamond characteristics
A
- 4 covalent bonds —> makes it very hard
- Hight melting + boiling point - strong covalent bonds - take a lot of energy to break
- doesn’t conduct electricity - no free electrons or ions.
9
Q
Graphite characteristics
A
- Made just of carbon
- 3 covalent bonds- creates layers of hexagons
- High melting + boiling points- strong covalent bonds- take lots of energy to overcome
- Weak attraction between layers- layers slide easily (soft)
- One delocalised electron- so can conduct electricity
10
Q
Silicon dioxide characteristics
A
- Made up of carbon and oxygen atoms
- Each carbon has 4 strong covalent bonds - high melting and boiling point
- Each oxygen has 2 strong covalent bonds- high melting and boiling point
- Wont conduct electricity- no free electrons
11
Q
Metallic bonding
A
- Involves delocalised electrons - can conduct electricity
- Strong electrostatic attraction between positive metal ions and negative electrons- high mp + bp
- Metal ions can slide- malleable
12
Q
What is an alloy?
A
A mixture of 2 or more metals or a metal and another element.
