Bonding

Question 1

What is an ionic bond? (2)

Answer 1

A bond formed from the electrostatic attraction (1) between two ions. (1)

Question 2

How is an ion formed? (2)

Answer 2

An ion is formed when an atom gains/loses electrons to form a charged atom (1) with a maximum number of outer electrons. (1)

Question 3

What is meant by a giant ionic structure? (1)

Answer 3

A giant ionic lattice structure in which each ion is surrounded by ions of the opposite charge. (1)

Question 4

List 3 properties of giant ionic structures. (3)

Answer 4

1. High melting and boiling points. (1)
2. The ions are in a fixed position and so can’t carry an electric charge. (1)
3. When dissolved in water the ions are free to move so they can carry a charge. (1)

Question 5

Why do ionic substances usually have high melting and boiling points. (1)

Answer 5

The strong electrostatic attraction means a lot of energy is required to break the strong bonds. (1)

Question 6

Work out the ionic formula for Aluminium Oxide. (2)

Answer 6

Al³⁺ + O²⁻ –> Al₂O₃ (2)

Question 7

Work out the ionic formula for Iron (II) Chloride. (2)

Answer 7

Fe²⁺ + Cl⁻ –> FeCl₂ (2)

Question 8

What is a compound ion? (1)

Answer 8

When a compound becomes charged like an ion. (1)

Question 9

What is the formula for a positive ammonium ion? (1)

Answer 9

NH₄⁺ (1)

Question 10

What is the formula for a negative hydroxide ion? (1)

Answer 10

OH⁻ (1)

Question 11

Work out the ionic formula for aluminium nitrate. (2)

Answer 11

Al³⁺ + NO₃⁻ –> Al(NO₃)₃ (2)

Question 12

What is a covalent bond? (1)

Answer 12

A bond in which the atoms share electrons to achieve a full outer electron shell. (1)

Question 13

List 2 properties of simple covalent molecules. (2)

Answer 13

1. Low melting and boiling points (1)
2. Can’t carry an electric charge due to having no charged particles. (1)

Question 14

Why do simple covalent molecules have low melting and boiling points? (2)

Answer 14

Because the molecules are held together via weak intermolecular forces (1), making them easy to break with enough energy. (1)

Question 15

What is a giant covalent structure? (1)

Answer 15

When many atoms share electrons to form a large solid structure.(1)

Question 16

Name 3 examples of giant covalent structures. (3)

Answer 16

1. Diamond (1)
2. Graphite (1)
3. Silicon dioxide (1)

Question 17

Why do giant covalent structures have high melting and boiling points? (1)

Answer 17

Because they contain many strong covalent bonds that require lots of energy to break. (1)

Question 18

How is graphite different to other covalent structures? (2)

Answer 18

It’s able to conduct electricity (1) due to having delocalised electrons between the layers. (1)

Question 19

What is a fullerene? (2)

Answer 19

A hollow cage (1) formed by a finite number of carbon atoms. (1)

Question 20

How large are nanoparticles? (1)

Answer 20

Between 1-100 nanometres. (1)

Question 21

How do we work out for surface area to volume ratio in 4 steps? (4)

Answer 21

1. Work out the surface area of the shape. (1)
2. Work out the volume of the shape (1)
3. Write a ratio between the two (1)
4. Divide both sides by the volume such that the ratio is in the form n:1 (1)

Question 22

List 3 limitations to bonding models. (3)

Answer 22

1. They are not to scale/not accurate. (1)
2. Some indicate 3-dimensionality and some don’t. (1)
3. Some show all the electrons and others don’t show all the electrons or energy shells. (1)

Question 23

How do metals form positive ions? (1)

Answer 23

By losing electrons and becoming positive. (1)

Question 24

What happens to the electrons lost from the metal ion? (1)

Answer 24

They become delocalised/free to move around. (1)

Question 25

What is a metallic bond? (2)

Answer 25

A bond formed from the electrostatic attraction (1) between positive metal ions and the delocalised electrons in the metal (1)

Question 26

Why do metals conduct electricity? (3)

Answer 26

The delocalised electrons (1) within the metal are free to move around (1) and carry a charge. (1)

Question 27

What is a pure metal? (1)

Answer 27

A metallic substance made up of only one type of metal atom. (1)

Question 28

What is an alloy? (2)

Answer 28

A metallic substance that is a a mixture of multiple types of metal atoms (as well as a few non-metal atoms) (1) commonly bonded to the delocalised electrons (1)

Question 29

Why are pure metals soft? (3)

Answer 29

In pure metals, the atoms are all the same size (1) and so they form layers (1) that can slide past each other, making them malleable. (1)

Question 30

Why are alloys harder than pure metals? (3)

Answer 30

In alloys, the different atoms are all different sizes (1), distorting the layers (1) and making it harder for them to slide past each other. (1)