Bonding

Question 1

What are the two kind of substances that use covalent bonding?

Answer 1

Simple mollecular and Giant covalent

Question 2

What are the boiling and melting points of simple mollecular like?

Answer 2

They are both very low

Question 3

Why are the boiling melting points very low?

Answer 3

They have weak intermolecular forces holding them together so the molecules are easily parted from each other

Question 4

What kind of state are most simple molecular substances?

Answer 4

Gas and liquid (at room temperature)

Question 5

What are the boiling and melting points like in giant covalent?

Answer 5

Both are very high

Question 6

Why are the boiling and melting points very high?

Answer 6

Because they have lots of strong covalent bonds which means it takes a lot of energy to break them all

Question 7

Do they conduct electricity?

Answer 7

No (except for graphite)

Question 8

Are they soluble or insoluble in water?

Answer 8

Insoluble

Question 9

Give two examples of giant covalent substances

Answer 9

Diamond and graphite

Question 10

In Diamond how many bonds does each carbon atom form?

Answer 10

4

Question 11

In graphite how many bonds does each carbon atom form?

Answer 11

3

Question 12

Between what kind of elements does covalent bonding occur?

Answer 12

Between non-metals

Question 13

Give a definition for oxidation?

Answer 13

When an atom loses and electron

Question 14

Give a definition for reduction?

Answer 14

When an atom gains an electron

Question 15

What are cations?

Answer 15

Positive ions

Question 16

What are anions?

Answer 16

Negative ions

Question 17

What are the melting and boiling points like in giant ionic structures?

Answer 17

They are both very high

Question 18

Why are the boiling and melting points like this?

Answer 18

There is a very strong electrostatic attraction between the two oppositely charged ions so a lot of energy is required to over come the attraction

Question 19

Describe bonding in metals

Answer 19

Metals have a giant structure of positive ions surrounded by a sea of delocalised electrons. The attraction between the positive ions and electrons is called metallic bonding.

Question 20

Explain why most metals are malleable

Answer 20

Because they have layers of ions that can slide of each other

Question 21

Why are metals good conductors of electricity and heat?

Answer 21

The free electrons carry electrical current and heat energy through the material

Question 22

When do ionic compounds conduct electricity and why?

Answer 22

When molten or in solution. They are made in a lattice so when solid don’t conduct electricity because the ions aren’t free to move around. When an ionic compound is dissolved or melted, the ions separate and are free to move in the solution. So they can carry electric current and so conduct electricity.