C3.9/10 - Metals + metallic bonding Flashcards
1
Q
Metallic bonding
A
-occurs between metals only
2
Q
Metals are ..
A
- giant lattices of positively charged ions
- arranged in regular patterns on top of each other
3
Q
Process of metallic bonding
A
- outer electrons of metals become delocalised
- forming positive metal ions
- a sea of electrons is formed by the free electrons to surround the ions
- strong electrostatic attraction occurs between the electrons + ions = bonded
4
Q
Properties of metals
A
- high melting/boiling points
- malleable
- good conductors of heat/electricity
5
Q
Why do metals have high melting/boiling properties?
A
-due to strong metallic bonds
6
Q
Why are metals malleable?
A
-as atoms are arranged in regular layers that can slide over each other
7
Q
Why are metals good conductors?
A
- due to their delocalised electrons
- they can carry charge through the metal
8
Q
Pure metals - eg iron
A
- held together by giant metallic structure
- atoms are arranged in tightly packed layers
- so they can slide over each other
- making iron soft
9
Q
pure metals are different to alloys as they..
A
are softer
10
Q
Alloys meaning
A
- a mixture of 2/more elements
- 1 element must be a metal
11
Q
Alloy - steel features:
A
- iron mixed with carbon atoms
- as carbon atoms are a different size
- they do not form regular layers
- making it harder for them to slide over each other
- making steel hard
12
Q
Why are alloys harder than pure metals?
A
- as the other elements in the alloy will be a different size to the metal atoms
- they will not form a regular layer
- the layers will not be able to slide over each other
- making it a harder material
13
Q
Why are metals malleable?
A
- the delocalised electrons in the lattice cause it to move out of shape
- when struck, metal atoms can slip past one another
- making them malleable
14
Q
What does it mean if metals are ductile?
A
they can be drawn into wires
15
Q
Why do metals have high melting points?
A
- their giant structures
- means that their electrostatic forces extend in all directions
- so it takes a lot of energy to separate them and break down the lattice
