C3: Structure & Bonding

Question 1

What happens in metallic bonding?

Answer 1

The particles which are atoms share delocalised electrons

Question 2

How are ionic compounds held together?

Answer 2

By strong electrostatic forces of attraction between the oppositely charged ions.

Question 3

What are ionic compounds always?

Answer 3

Giant

Question 4

What large molecules have covalent bonds?

Answer 4

Polymers

Question 5

What are 2 giant covalent structures?

Answer 5

Diamond and silicon dioxide

Question 6

What does the amount of energy needed to change a substances state depend on?

Answer 6

The strength of the forces between the particles

Question 7

What is the relationship between melting and boiling point, and the strength of the forces between particles?

Answer 7

The stronger the forces, the higher the melting and the boiling point

Question 8

What are 3 limitations of the simple model?

Answer 8

The model has no forces, all the particles are represented as spheres and that they are solid

Question 9

What are 2 properties of ionic compounds?

Answer 9

They have high melting and boiling points due to the large amount of energy needed to break the strong bonds and they conduct electricity when molten or dissolved due to ions being free to move around and carry charge

Question 10

What are 3 properties of small molecules?

Answer 10

Gases or liquids, so low melting and boiling points, weak intermolecular forces (which break when heated) and do not conduct electricity as the molecules do not have an overall charge

Question 11

What does each carbon atom in diamond form?

Answer 11

4 covalent bonds

Question 12

What are 3 physical properties of diamond?

Answer 12

Hard, have high melting and boiling points, and do not conduct electricity

Question 13

What does each carbon atom in graphite form?

Answer 13

3 covalent bonds

Question 14

What shape are the rings in the layers of graphite?

Answer 14

Hexagonal

Question 15

What is graphene useful for?

Answer 15

Electronics and composites

Question 16

What are fullerenes?

Answer 16

Molecules of carbon atoms with hollow shapes

Question 17

What shape was the buckminsterfullerene?

Answer 17

Spherical

Question 18

What shape are carbon nanotubes? What are they useful for?

Answer 18

Cylindrical. Electronics, nanotechnology and materials

Question 19

What are the diameters of nanoparticles?

Answer 19

Between 100 - 2500nm

Question 20

What are some applications of nanoparticles?

Answer 20

Suncream, deodrants and catalysts

Question 21

What type of structures do metals have?

Answer 21

Giant

Question 22

Why are metals good conductors of electricity? Why are they good conductors of thermal energy?

Answer 22

Because they have delocalised electrons that carry electrical charge. This is because energy is transferred by the delocalised electrons

Question 23

Why are the elements in group 3, 4, and 5 not considered ions?

Answer 23

Because they would have to lose or gain 3 or 4 electrons, which requires lots of energy

Question 24

When do you know which way reactants go in half equations?

Answer 24

If the atom is becoming a positive ion and loses electrons, the electron is on the right

Question 25

What is a disadvantage of displayed formulas when represent covalent bonds?

Answer 25

They don’t show the 3D shape of the molecule

Question 26

What is a disadvantage of 3D model when representing covalent bonds?

Answer 26

Hard to predict what shape the molecule will make

Question 27

What are examples of small molecular forces?

Answer 27

Ammonia, chlorine, water and methane

Question 28

Why does the boiling point increase as you go down group 7?

Answer 28

Because the molecules get larger, so there are more intermolecular forces present

Question 29

What are allotropes?

Answer 29

Different structural forms of the same element in the same physical state

Question 30

Why is graphite soft?

Answer 30

No covalent bonds between layers, so can slide over each other

Question 31

Why are nanoparticles seen to be dangerous?

Answer 31

They have a large SA:Vol ratio, so if a spark happened, it would be very dangerous for a large quantity. Also, if they’re used more and more, that would be found in the atmosphere easily, which could damage lungs if breathed in