Topic 1.3- Key concepts

Question 1

Why can elements be classified as Ionic, Simple/giant covalent, or metallic.

Answer 1

-Different atoms cuase different bonds:
- Ionic, Covalent or metallic bonds.

Question 2

What and why is Ionic melting point?

Answer 2

-High
-Strong electrostatic forces between the positive metal and negative gas

Question 3

What and why is simple molecular melting point?

Answer 3

-Low
-Weak intermolecular forces between molecules

Question 4

What and why is giant covalent melting point?

Answer 4

-High
-It is one molecule and therefore has no weak intermolecular forces
-Strong electrostatic forces

Question 5

What and why is Metallic melting point?

Answer 5

-High
-Strong electrostatic forces between delocalised electrons and positive ions.

Question 6

What and why is Ionic bonds physical state?

Answer 6

-solid
-high melting point

Question 7

What and why is simple molecular bonds physical state?

Answer 7

-gas
-low melting point

Question 8

What and why is giant covalent bonds physical state?

Answer 8

-solid
-high melting point

Question 9

What and why is metallic bonds physical state?

Answer 9

-solid high melting point

Question 10

What and why is Ionic solubility in water?

Answer 10

• Many are soluble
• Water molecules ( electrons are generally closer to oxygen as oxygen has more protons)
• In water Oxygen is more negative and hydrogens are more positive
• Positive metal will move to oxygen
• Negative gas will move to hydrogen

Question 11

What and why is simple molecular solubility in water?

Answer 11

• Few are soluble
  -Water is polar and simple molecular structures are normally non-polar

Question 12

What and why is giant covelant solubility in water?

Answer 12

-Insoluble
-Strong covalent bonds

Question 13

What and why is metallic solubility in water?

Answer 13

-Insoluble
-Non polar and water is polar

Question 14

What and why does/ doesn’t Ionic conduct electricity?

Answer 14

-Only in molten form/ in solution
- Ions can move freely

Question 15

What and why does/ doesn’t simple molecular conduct electricity?

Answer 15

• Most do not
• they are neutral

Question 16

What and why does/ doesn’t giant covalent conduct electricity?

Answer 16

• Most do not conduct
• Most have no free electrons

Question 17

What and why does/ doesn’t metallic conduct electricity?

Answer 17

• Can conduct
• Free delocalised electrons

Question 18

What are two main examples of giant covalent structures made of carbon?

Answer 18

• Diamond
• Graphite

Question 19

What is the structure of graphite?

Answer 19

• One atom thick
• Light
• Strong
• Conducts electricity
• Low melting and boiling point

Question 20

Why can graphite conduct electricity?

Answer 20

• Graphite is made of three carbon atoms bonded to one carbon atom
• Carbon has 4 electrons on outer shell
• One free electron
• Hexagonal shape
• High melting point

Question 21

Why does graphite have a low boiling point?

Answer 21

• Weak intermolecular forces between the one atom thick layers.

Question 22

Properties of diamond?

Answer 22

• Very strong
• High melting/ boiling point
• Does not conduct electricity
• rigid lattice structure

Question 23

Why can’t diamonds conduct electricity?

Answer 23

• Carbon has four bonds each, no free electrons

Question 24

Why do diamonds have a high melting/boiling point?

Answer 24

• No weak intermolecular forces
• All strong covalent bonds between atoms

Question 25

Why is diamond used in cutting?

Answer 25

• Strong
• Hard
• strong covalent bonds

Question 26

Why is graphite used in lubrication?

Answer 26

• Hexagonal sheets can slide past each-other due to weak intermolecular forces.
• Soft, slippery
• High melting point due to strong covalent bonds

Question 27

Why is graphite used in electrodes?

Answer 27

• Free electron

Question 28

What is graphene and what are its properties?

Answer 28

• One layer of graphite
• Conducts electricity (free electrons)
• High melting/boiling point (no layers, no weak intermolecular forces)

Question 29

What are fullerenes?

Answer 29

-Hollow carbon structures
- Made of hexagonal shapes
( could have parts of 5, or 7 connected, pentagonal or heptagonal)

Question 30

What was the first fullerene

Answer 30

• Buckminsterfullerene
• 60 carbon atoms
• Ball shape

Question 31

What are the uses of fullerenes like Buckminsterfullerene?

Answer 31

• Deliver drugs
• Lubricants
• Catalysts

Question 32

Uses of carbon Nanotubes?

Answer 32

• Very long, small diameter
• Extremely elastic
• Reinforce materials ( tennis rackets)

Question 33

Describe poly(ethene)

Answer 33

• C2H4
• chain of carbon that consists of large molecules
• Hydrocarbon

Question 34

Metals properties?

Answer 34

• Conduct electricity - free delocalised electrons
• Malleable, uniform layers can slide over each-other.

Question 35

Describe most metals?

Answer 35

• High melting and boiling point
• Shiny
• Conduct electricity well

Question 36

Describe most non- metals

Answer 36

• Low melting and boiling point
• poor conductors of electricity

Question 37

Limitations of the dot and cross diagram?

Answer 37

• Not 3-D
• looks like electrons are different

Question 38

Limitations of the ball and stick diagram?

Answer 38

• Atoms are far apart
• Doesn’t include electrons are protons

Question 39

Ideas needed to see in models?

Answer 39

• Electrons the same
• Protons
• 3-D
• Bonded and close together
• Respective sizes of atoms
• Number of atoms included