Unit 2: Bonding

Question 1

What charge do electrons have?

Answer 1

-1

Question 2

What charge will an ion of lithium take?

Answer 2

1+ (one electron in the outer shell, needs to lose it)

Question 3

What charge will an ion of beryllium take?

Answer 3

2+ (two electrons in the outer shell, needs to lose them both)

Question 4

What charge will an ion of barium take?

Answer 4

2+ (group 2 so two electrons in the outer shell, needs to lose them both)

Question 5

What charge will an ion of fluorine take?

Answer 5

1- (7 electrons in the outer shell, needs to gain one)

Question 6

If something has gained electrons, what charge will it have?

Answer 6

Negative

Question 7

If something has lost electrons, what charge will it have?

Answer 7

Positive (because they have lost a negative!)

Question 8

What is reduction in terms of electrons?

Answer 8

Reduction is gain of electrons

Question 9

What is oxidation in terms of electrons?

Answer 9

Oxidation is lossof electrons

Question 10

Why do atoms transfer electrons in ionic bonding?

Answer 10

So that they can have full outer shells

Question 11

Why do sodium ions and chlorine ions form an ionic bond?

Answer 11

There is an electrostatic force of attraction between oppositely charged ions

Question 12

What is the name for a substance made of billions of oppositely charged ions joined together?

Answer 12

Giant ionic lattice

Question 13

Define giant ionic lattice

Answer 13

A huge 3D network of ions

Question 14

State the melting points of ionic substances

Answer 14

High

Question 15

What is an ionic bond?

Answer 15

Strong electrostatic attraction between oppositely charged ions

Question 16

Explain why ionic substances have high melting points.

Answer 16

Strong bonds between oppositely charged ions are hard to break

Question 17

Will NaCl(s) conduct electricity?

Answer 17

No- (s) is solid

Question 18

Will NaCl (aq) conduct electricity?

Answer 18

Yes (aq stands for aqueous which means it is dissolved in water)

Question 19

Will NaCl (l) conduct electricity?

Answer 19

Yes- (l) is liquid or molten

Question 20

Explain why ionic compounds do not conduct electricity when solid

Answer 20

Because the ions are not free to move

Question 21

Explain why ionic compounds conduct electricity in solution

Answer 21

Because the ions are free to move

Question 22

When do ionic bonds form?

Answer 22

Between a metal and a non-metal

Question 23

Explain why ionic compounds conduct electricity when molten

Answer 23

Because the ions are free to move

Question 24

What does soluble mean?

Answer 24

Dissolves in water

Question 25

What does insoluble mean?

Answer 25

Does not dissolve in water

Question 26

Explain why chlorine and fluorine form covalent bonds

Answer 26

They are both non-metals

Question 27

Complete the sentence: In covalent bonds, electrons are _______________________

Answer 27

Shared

Question 28

In ionic bonds, electrons are ___________________

Answer 28

Transferred

Question 29

What is the name given to the structure of diamond, graphite and silicon dioxide?

Answer 29

Giant covalent

Question 30

How many bonds does each carbon have in diamond?

Answer 30

4

Question 31

Explain why diamond has a high melting point

Answer 31

Giant structure, Strong covalent bonds between the atoms, requires a lot of energy to break

Question 32

Explain why most giant covalent substances do not conduct electricity (3 marks)

Answer 32

There are no electrons/ions/charged particles that are free to move

Question 33

Explain why graphite conducts electricity

Answer 33

Has delocalised electrons between the layers that can move through the graphite

Question 34

Explain why graphite can act as a lubricant

Answer 34

Weak forces between layers which are free to slide over each other

Question 35

What is graphene?

Answer 35

One layer of graphite

Question 36

What type of substance are methane and water?

Answer 36

Simple molecular (or simple molecules)

Question 37

What is a molecule?

Answer 37

A group of atoms chemically bonded together

Question 38

Describe the structure of simple covalent molecules

Answer 38

Strong covalent bonds between atoms, weak forces holding the molecules together

Question 39

What are intermolecular forces?

Answer 39

Weak forces between molecules which hold them together

Question 40

Explain why methane has a low melting point

Answer 40

It is a simple molecular substance with weak forces between the molecules (which are easy to break)

Question 41

What is a polymer?

Answer 41

Millions of small molecules joined together in a chain to form a large molecule

Question 42

Describe the main features of metals in terms of their structure

Answer 42

Positive metal ions arranged in layers with delocalised electrons

Question 43

Explain why metals can conduct electricity

Answer 43

Delocalised electrons are free to carry charge

Question 44

Explain why pure metals are soft

Answer 44

Layers of metal ions are free to slide over each other

Question 45

What is an alloy?

Answer 45

A mixture of two or more elements, at least one of which is a metal

Question 46

Give a reason for alloying a metal

Answer 46

To make it harder, to make it less reactive

Question 47

Explain why alloys can be harder than pure metals

Answer 47

Different size of atoms disturb the layers to stop them sliding over each other

Question 48

What is the reactivity series?

Answer 48

A list of elements ordered by their reactivity

Question 49

What type of ion do metals from?

Answer 49

Positive Ion

Question 50

What type of ion do non-metals form?

Answer 50

Negative ion