Structures

Question 1

What is the structure of the giant ionic lattice?

Answer 1

Strong electrostatic forces attraction between oppositely charged ions

Question 2

What is the bonds between giant ionic lattice?

Answer 2

Ionic bonds

Question 3

Why is there high boiling and melting points in a giant ionic lattice?

Answer 3

High melting and boiling points because substantial amount of energy is needed to break the strong ionic bonds

Question 4

Can giant ionic lattices conduct electricity?

Answer 4

In solid state the negative ions cannot move or carry charge therefore don’t conduct electricity. However if the ionic solid is melted it can move and carry charge

Question 5

Are giant ionic lattices soluble in water?

Answer 5

Most ionic compound are soluble in water and form aqueous solutions

Question 6

What is the structure of molecular covalent structures?

Answer 6

Strong covalent bonds between compounds with weak van set waal forces between the molecules

Question 7

Why is there low melting and boiling points in a molecular covalent structure?

Answer 7

Little energy is needed to break the weak forces between the molecules so there is low melting and boiling points

Question 8

Does molecular covalent bonds conduct electricity?

Answer 8

The covalent molecular substances do not conduct electricity because the molecules are neutral and there are no charged particles (ions or neutrons) to move and carry charge

Question 9

Are molecular covalent structures soluble in water?

Answer 9

Insoluble in water as they don’t form intermolecular bonds with water

Question 10

What is an allotrope?

Answer 10

Different forms of the same element in the same physical state

Question 11

What are the allotropes of carbon?

Answer 11

Diamond, graphite, graphene

Question 12

What is the structure of a diamond?

Answer 12

Each carbon atom is bonded to 4 others in a tetrahedral shape

Question 13

Why does a diamond have high melting and boiling points?

Answer 13

Substantial amount of energy is needed to break the strong covalent bonds

Question 14

Does a diamond conduct electricity?

Answer 14

There are no free ions or delocalised electrons to move and carry the charge

Question 15

Why is a diamond soo hard?

Answer 15

It is hard due to the 3-D tetrahedral structure with strong covalent bonds

Question 16

What is the structure of graphite?

Answer 16

Layers of carbon arranged in hexagons with covalent bonds between atoms and weak forces between layers - one electron per carbon atom is delocalised

Question 17

Why is there high boiling and melting points in graphite?

Answer 17

High melting and boiling points as substantial amount of energy is needed to break the covalent bonds

Question 18

Can graphite conduct electricity?

Answer 18

It can conduct electricity sonar there are delocalised electrons which carry charge

Question 19

Is graphite hard?

Answer 19

No

It is soft because the weak forces between the layers allow the layers to slide

Question 20

What is the structure of graphene?

Answer 20

A single atom thick layer of graphite with strong covalent bonds between each carbon atom: the atoms are arranged in hexagons

Question 21

Why are there high melting and boiling points in graphene?

Answer 21

High melting and boiling points because covalent bonds are strong and substantial amount of energy is needed to break it

Question 22

Does graphene conduct electricity?

Answer 22

Good conductor of electricity as one electron per atom is unbonded and is free to carry charge

Question 23

Is graphene strong?

Answer 23

Very strong as there are strong covalent bonds in the layers. It is light and the thinnest material possible and transparent due to the one layer of atoms

Question 24

What is the structure of a metallic lattice?

Answer 24

A 3-D structure of positive ions and Delano slides electrons bonded by metallic bonds

Question 25

So metallic lattices have high melting and boiling points?

Answer 25

Metals have high melting and boiling points because the metallic bond (attraction between the positive and delocalised electrons) is strong and takes substantial amount of energy to break

Question 26

Are metallic lattices good conductors of electricity?

Answer 26

Metals are good conductors of electricity because the delocalised electrons can move and carry charge

Question 27

Why are metallic lattices malleable and ductile?

Answer 27

Metals are malleable and ductile because the layers of ions can slide over each other, yet the delocalised electrons still attract the ions and hold the structure together - the metallic bond is not disrupted

Question 28

What is an alloy?

Answer 28

A mixture of two or more elements, at least one of which is a metal, and the resulting mixture has metallic properties?

Question 29

Why are alloys harder than pure metal?

Answer 29

Alloys contain ions or atoms of different sizes, which distort the regular arrangement. This makes it more difficult for the layers to slide over each other, so alloys are harder than pure metals.

Question 30

Why is gold alloys used instead of pure gold?

Answer 30

Pure gold is rarely used in jewellery as it is too soft. Instead gold alloys are used containing other elements.

Question 31

What is the purity of gold measured in?

Answer 31

The purity of gold is measured in CARATS ( pure gold is 24 carats)

Question 32

How to measure the purity of gold?

Answer 32

% of gold in alloy = number of carats/24 X 100