Unit 2 Structure and Bonding Core questions

Question 1

When does ionic bonding occur?

Answer 1

When a metal and non-metal react

Question 2

When does covalent bonding occur?

Answer 2

When non-metals react

Question 3

When does metallic bonding occur?

Answer 3

When metals react

Question 4

What is an ionic bond?

Answer 4

The electrostatic attraction between oppositely charged ions

Question 5

What is a covalent bond?

Answer 5

The electrostatic attraction between the positive nuclei of atoms and the shared, negative electrons between them

Question 6

What is a metallic bond?

Answer 6

The electrostatic attraction between positive metal ions and the delocalised electrons

Question 7

What charge will an ion of lithium have?

Answer 7

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

Question 8

What charge will an ion of beryllium have?

Answer 8

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

Question 9

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

Answer 9

Negative

Question 10

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

Answer 10

Positive (because they have lost a negative!)

Question 11

What charge will an ion of oxygen have?

Answer 11

-2 (6 electrons in outer shell so needs to gain two)

Question 12

What charge will an ion of Selenium have?

Answer 12

-2 (group 6, so has 6 electrons in the outer shell and needs to gain two)

Question 13

Explain in terms of electrons what occurs when lithium bonds with chlorine

Answer 13

One electron lost from lithium and it is gained by chlorine

Question 14

Why do atoms transfer electrons in ionic bonding?

Answer 14

So that they can have full outer shells

Question 15

Explain in terms of electrons what occurs when lithium bonds with fluorine

Answer 15

One electron lost from lithium and it is gained by fluorine

Question 16

Explain in terms of electrons what occurs when magnesium bonds with oxygen

Answer 16

Two electrons lost from magnesium and they are both gained by oxygen

Question 17

Explain in terms of electrons what occurs when beryllium bonds with oxygen (3 marks)

Answer 17

Two electrons lost from beryllium and they are both gained by oxygen

Question 18

Explain in terms of electrons what occurs when magnesium bonds with chlorine

Answer 18

Two electrons are lost from magnesium and two different chlorine atoms each gain 1 electron

Question 19

Explain in terms of electrons what occurs when sodium bonds with oxygen

Answer 19

two different sodium atoms lose one electron and an oxygen atom gains both

Question 20

Why don’t sulphur ions and oxygen ions form ionic bonds with each other?

Answer 20

Both have negative charges so would repel

Question 21

What is the name for the structure of a solid ionic compound?

Answer 21

Giant ionic lattice

Question 22

Define giant ionic lattice

Answer 22

A huge 3D network of ions

Question 23

State the melting points of ionic substances

Answer 23

High

Question 24

State the melting points of ionic substances

Answer 24

High

Question 25

Explain why ionic substances have high melting points

Answer 25

Strong ionic bonds between oppositely charged ions require lots of energy to break

Question 26

Will a solid ionic compound conduct electricity and why?

Answer 26

No, because the ions are held firmly in place

Question 27

Will a molten ionic compound conduct electricity?

Answer 27

Yes, as the ions are free to move so can carry a charge

Question 28

What does molten mean?

Answer 28

Melted

Question 29

What does (aq) stand for?

Answer 29

Aqueous, which means dissolved in water

Question 30

What does soluble mean?

Answer 30

Dissolves in water

Question 31

What does insoluble mean?

Answer 31

Does not dissolve in water

Question 32

Magnesium carbonate is insoluble. What do you need to do before it will conduct electricity?

Answer 32

Melt it

Question 33

Sodium fluoride is soluble. Explain what the easiest way for it to conduct electricity is

Answer 33

Dissolve it in water because this does not require high temperatures

Question 34

Explain why chlorine and fluorine form covalent bonds

Answer 34

They are both non-metals

Question 35

What happens in covalent bonding?

Answer 35

Atoms share a pair of electrons

Question 36

How many covalent bonds will a group 7 element make?

Answer 36

1 as they need one more electron for a full outer shell

Question 37

How many covalent bonds will a group 6 element make?

Answer 37

2 as they need two more electrons for a full outer shell

Question 38

How many covalent bonds will a group 5 element make?

Answer 38

3 as they need three more electrons for a full outer shell

Question 39

How many electrons does hydrogen have when it has a full outer shell?

Answer 39

2 as the first shell only holds 2 electrons

Question 40

How many covalent bonds does hydrogen make?

Answer 40

1 as it only needs one more electron for a full outer shell. It also only has 1 electron to share!

Question 41

In ionic bonds, electrons are ___________________

Answer 41

Transferred from a metal atom to a non-metal

Question 42

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

Answer 42

Giant covalent

Question 43

How many bonds does each carbon have in diamond?

Answer 43

4

Question 44

Explain why diamond has a high melting point

Answer 44

It has a giant covalent structure. The strong covalent bonds between the atoms require a lot of energy to break

Question 45

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

Answer 45

There are no mobile electrons/ions to carry a charge

Question 46

Explain why graphite conducts electricity

Answer 46

Carbon only makes 3 bonds, each carbon has a delocalised electron that can move through the graphite

Question 47

Explain why graphite can act as a lubricant

Answer 47

Layers of atoms can slide over each other

Question 48

What is graphene?

Answer 48

One layer of graphite

Question 49

What is a fullerene?

Answer 49

Substance made of carbon atoms arranged in a cage

Question 50

What type of substance are methane and water?

Answer 50

Simple molecular (or simple covalent molecules)

Question 51

What is a molecule?

Answer 51

A group of atoms chemically bonded together

Question 52

Describe the structure of simple covalent molecules

Answer 52

Strong covalent bonds between atoms, weak intermolecular forces between the molecules

Question 53

What are intermolecular forces?

Answer 53

Weak forces between molecules which hold them together

Question 54

Explain why molecular substances have a low melting point?

Answer 54

Weak intermolecular forces between the molecules which require little energy to break

Question 55

What is a polymer?

Answer 55

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

Question 56

Describe the structure of metals

Answer 56

Positive metal ions arranged in layers with delocalised electrons

Question 57

Explain why metals can conduct electricity

Answer 57

Have a delocalised electrons can carry a charge

Question 58

Explain why pure metals are soft

Answer 58

Layers of metal ions can slide over each other

Question 59

What is an alloy?

Answer 59

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

Question 60

Give a reason for alloying a metal

Answer 60

To make it harder | To make it less reactive

Question 61

Explain why alloys can be harder than pure metals

Answer 61

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

Question 62

Why do metals conduct heat?

Answer 62

Delocalised electrons can move and transfer energy

Question 63

What happens at the melting point?

Answer 63

A substance goes from solid to liquid or from liquid to solid

Question 64

What happens at the boiling point?

Answer 64

A substance goes from liquid to gas or from gas to liquid

Question 65

What is a nanoparticle?

Answer 65

A particle between 1 and 100 nm in size

Question 66

Why are nanoparticles useful?

Answer 66

They have a high surface area to volume ratio. This means they have unique properties and smaller quantities are needed to be effective

Question 67

What are some uses of nanoparticles?

Answer 67

They are used in medicine, electronics, cosmetics, sun creams, deodorants and as catalysts.

Question 68

What are some risks of nanoparticles?

Answer 68

They are still new so haven't been studied in detail yet and they may cause harmful effects to the human body