topic 2: bonding, structure and properties of matter

Question 1

What type of intermolecular forces do covalent bonds have?

Answer 1

Weak

Question 2

How would you describe the covalent bond between atoms in covalent structures?

Answer 2

Strong

Question 3

What happens to electrons in covalent bonds?

Answer 3

Pairs or a pair of electrons are shared.

Question 4

Are simple covalent structures good or poor conductors of electricity?

Answer 4

Poor.

Question 5

What is the structure pf an ionic compound called?

Answer 5

Ionic lattice.

Question 6

What is an ion?

Answer 6

A charged particle.

Question 7

What type of attraction occurs between ions in ionic structures?

Answer 7

Electrostatic attraction.

Question 8

What happens to electrons in ionic bonds?

Answer 8

They are transferred. An atom will either lose or gain electrons.

Question 9

Why do elements want to lose or gain electrons?

Answer 9

To achieve a full outer shell.

Question 10

Between what type of elements do ionic bonds occur?

Answer 10

A metal and non-metal.

Question 11

Between what type of elements do covalent bonds occur?

Answer 11

Two non-metals.

Question 12

What type of melting/boiling points do simple covalent molecules have?

Answer 12

Low.

Question 13

Why do simple covalent molecules have low melting points?

Answer 13

Because there are weak intermolecular forces between molecules that are easily broken.

Question 14

Diamond, graphite and silicon dioxide are all examples of what?

Answer 14

Giant covalent structues.

Question 15

Does diamond conduct electricity?

Answer 15

No.

Question 16

What type of melting point does diamond have?

Answer 16

Very high.

Question 17

What is diamond used for?

Answer 17

Jewellery, cutting tools.

Question 18

Describe the structure of fullerenes.

Answer 18

Cage-like

Question 19

What are fullerenes used for?

Answer 19

Drug delivery in body.

Question 20

In diamond, each carbon atom is bonded to how many other carbon atoms?

Answer 20

4

Question 21

In graphite, each carbon atom is bonded to how many other carbon atoms?

Answer 21

3.

Question 22

Does graphite conduct electricity?

Answer 22

Yes.

Question 23

Why can graphite conduct electricity?

Answer 23

Because it contains delocalised electrons between layers.

Question 24

Describe the type of forces between layers in graphite.

Answer 24

Weak.

Question 25

Weak forces between layers in graphite allow them to what?

Answer 25

Slide over each other.

Question 26

What are uses of graphite?

Answer 26

Pencil leads, electrodes.

Question 27

Do metallic structures have high or low melting points?

Answer 27

High.

Question 28

What do metallic bonds occur between?

Answer 28

Two metals.

Question 29

Can metallic structures conduct electricity?

Answer 29

Yes.

Question 30

Why can metallic structures conduct electricity?

Answer 30

Because they contain delocalised electrons between layers.

Question 31

What are the electrons in metallic structures like?

Answer 31

Delocalised.

Question 32

Why are the positive ions in metallic structures attracted to the delocalised electrons?

Answer 32

Because of the electrostatic attraction between them.

Question 33

What are atoms arranged in in metallic structures?

Answer 33

Neat layers, regular pattern.

Question 34

Why do metallic structures have high melting points?

Answer 34

Because of the strong electrostatic attraction between the positive ions and delocalised electrons.

Question 35

Why are pure metals soft and malleable?

Answer 35

Because the atoms are all the same size and from neat layers which slide off easily, therefore easily wearing away.

Question 36

What is an alloy?

Answer 36

A mixture of metals/elements that aren’t chemically bonded.

Question 37

Name an example of an alloy.

Answer 37

Steel.

Question 38

Why are metals good thermal conductors?

Answer 38

Because the positive ions are tightly packed together and the delocalised electrons can move and carry heat energy.

Question 39

Why are alloys used more often than metals?

Answer 39

Because in the metallic structure, atoms are all the same size, forming neat layers that can slide off easily and can easily wear away. In alloys, atoms are not all the same size and form uneven layers that are less likely to slide off, therefore wearing away less easily.