Topic 2 - Bonding, Structure And Properties Of Matter

Question 1

When are ions made?

Answer 1

When electrons are transferred

Question 2

Why do atoms lose/gain electrons to form ions?

Answer 2

To get a full outer shell

Question 3

When metals form ions, do they lose or gain electrons?

Answer 3

Lose electrons to form positive ions

Question 4

When non-metals form ions, do they lose or gain electrons?

Answer 4

Gain electrons to form negative ions

Question 5

Which groups are most readily to form ions?

Answer 5

Groups 1,2 and 6,7

Question 6

What is ionic bonding?

Answer 6

Sharing electrons.

Metal + non metal

Question 7

What is the structure of ionic compounds?

Answer 7

They have a structure called a giant ionic lattice.

The ions form a tightly packet regular lattice arrangement there are very strong forces of attraction between oppositely charged ions.

Question 8

What are properties of ionic compounds?

Answer 8

High melting and boiling points due to strong bond between ions.
Cant conduct energy when solid but they can when liquid as the ions are free to move.
Dissolve easily in water.

Question 9

What is covalent bonding?

Answer 9

When 2 non-metals bond.

They share electrons to make covalent bonds.

Question 10

What are properties of simple molecular substances? (Eg H2 CL2 H2O)

Answer 10

Forces of attraction between molecules are weak but atoms within them have strong covalent bonds.

Low melting and boiling points to break intermolecular forces.

Gases or liquids at room temp.

As molecules get bigger, intermolecular forces are stronger so higher boiling and melting points.

Dont conduct electricity as they arent charged.

Question 11

What is a simple molecular substance?

Answer 11

They are made up of molecules containing atoms joined together by covalent bonds. Eg O2

Question 12

What is a polymer?

Answer 12

Long chains of repeating units.

There are lots of small units linked together to form a long molecule.

Question 13

How are atoms bonded in a polymer?

Answer 13

Covalently

Question 14

Do polymers have high or low boiling points?

Answer 14

Low

Question 15

What are features and examples of giant covalent structures?

Answer 15

In giant covalent structures, all atoms are bonded to each other by strong covalent bonds.

High melting/boiling points as lots of energy required to break bonds between atoms.

Dont conduct electricity.

Eg diamond, graphite, silicone

Question 16

What is an allotrope

Answer 16

Different structural forms of the same element

Question 17

What are the 4 allotropes of carbon?

Answer 17

Diamond
Graphite
Graphene
Fullerene

Question 18

What are features of diamond?

Answer 18

Made of carbon atoms that each form 4 covalent bonds. This forms a giant covalent structure

These strong bonds give diamond high melting point.

Doesnt conduct electricity since no free electrons or ions

Question 19

What are features of graphite?

Answer 19

Each carbon atom forms 3 covalent bonds. This forms sheets of carbon atoms arranged in hexagons.

No covalent bonds between sheets makes graphie soft and slippery so ideal lubricant.

High melting point.

Can conduct electricity and heat as each carbon atom has 1 delocalised electron.

Question 20

What are features of graphene?

Answer 20

Just one sheet of carbon atoms joined in hexagons. 1 atom thick.

Covalent bonds makes it very strong yet its very light.

Can conduct electricity since each carbon atom has 1 delocalised electrons.

Question 21

What are fullerenes?

Answer 21

They are molecules of carbon shaped like hollow balls.

Buckminster fullerene was the first fullerene to be discovered.

Question 22

What are uses of fullerenes?

Answer 22

Can be used to cage other molecules. Can use this function to deliver a drug into the body.

Have huge surface area so can help make great industrial catalysts(individual catalyst molecules can be attached to fullerenes).

Also make good lubricants.

Question 23

How can fullerenes be used in nanotechnology?

Answer 23

Fullerenes can form nanotubes.
Ratio between length and diameter of nanotubes is very high.
Nanotubes can conduct electricity and heat.
High tensile strength.
Can be used in electronics or to strengthen materials without adding much weight.

Question 24

How does metallic bonding work?

Answer 24

Involves delocalised electrons in outer shell of metals and their are strong forces of attraction between these shared negative electrons and position metal ions.

Question 25

Why are most metals solid at room temp?

Answer 25

Electrostatic forces of attraction between metal atoms and delocalised sea of electrons is very strong so requires lots of energy to break.

Question 26

Why are metals good conductors of electricity and heat?

Answer 26

The delocalised electrons are good conductors of electricity and heat.

Question 27

Why are most metals malleable?

Answer 27

Layers of atoms in a metal can slide over each other

Question 28

What is an alloy?

Answer 28

A mixture of 2 or more metals.

Harder and more useful than pure metals.

Question 29

What do the strength of forces of attraction between particles of a material rely on?

Answer 29

The material
The temperature
The pressure

Question 30

What are the features of a solid?

Answer 30

Strong forces of attraction between particles which holds them close together in fixed positions to form a regular lattice arrangement.

They dont flow, they have a definite shape and volume.

Particles vibrate - the hotter the solid is, the more they vibrate.

Question 31

What are the features of a liquid?

Answer 31

Weak forces of attraction between particles. Theyre randomly arranged and free to move past each other, but stick close together.

Definite volume but not shape.

Particles constantly moving with random motion. Hotter the liquid gets, the more they move

Question 32

What are the features of a gas?

Answer 32

Forces of attraction between particles is very weak. Theyre free to move and are far apart. They travel in straight lines.

No definite shape or volume.

Particles move constantly with random motion. The hotter the gas gets, the faster they move. When heated their pressure increases.

Question 33

What are some problems with the particle theory model?

Answer 33

Doesnt show forces between particle.

Particles in real life arena spheres

Question 34

Explain the process by which a solid goes to a gas.

Answer 34

When solid is heated, particles gain more energy.
This makes particles vibrate more which weakens forces holding the solid together.
When it reaches its melting point, the particles have enough energy to break free from positions. Solid turns into a liquid(MELTING).
When liquid is heated, particles gain more energy.
Energy makes particles move faster which weakens and breaks bonds holding liquid together.
At the boiling point, particles have enough energy to break their bonds.Liquid becomes a gas (BOILING/EVAPORATING).

Question 35

Explain the process by which a gas turns to a solid.

Answer 35

Gas cools so particles dont have enough energy to overcome forces of attraction between them.
Bonds form between particles.
At boiling point, so many bonds have formed that gas becomes liquid (CONDENSING)
When a liquid cools, particles have less energy so move less.
Not enough energy to overcome attraction between the particles so more bonds form between them.
At melting point, so many bonds have formed between particles so theyre held in place. (FREEZING)

Question 36

What does amount of energy needed for a substance to change state depend on?

Answer 36

Strength of forces between particles.

Question 37

Do nanoparticles have high surface area to volume ratio?

Answer 37

Yes

Question 38

What are some uses of nanoparticles?

Answer 38

Catalysts (huge SA:V ratio)
Nanomedicine - tiny particles like fullerenes absorbed by body more easily than most particles. Deliver drugs to right cells where theyre needed.
Silver nanoparticles have antibacterial properties. Used in surgical masks and wound dressings.
Cosmetics - used in moisturisers to make them less oily