Unit 2 - Bonding Structure And Properties Of Matter

Question 1

What are made when electrons are transferred

Answer 1

Ions

Question 2

What groups are most likely to form ions

Answer 2

1,2,6,7

Question 3

What structure if an ionic compound

Answer 3

Regular lattice structure

Question 4

Properties of ionic compound

Answer 4

High metlting and boiling points, strong bonds , can’t conduct electricity, ions separate free to move, carry electrical current

Question 5

What do covalent bonds usually have

Answer 5

Simple molecular structure

Question 6

Properties of covalent bond

Answer 6

String covalent bonds, weak intermolecular force, melting boiling points low, don’t conduct electricity, no free electrons or ions

Question 7

What are polymers

Answer 7

Lots of small units are linked together to form a long molecule. All atoms are joined by strong covalent bonds

Question 8

Name some giant covalent structures

Answer 8

Diamond, graphite, Graphene

Question 9

Properties of diamond

Answer 9

-Giant covalent structure
-4 covalent bonds
-really hard (lot of energy to break)
- high melting point
-don’t conduct electricity
-No free electrons

Question 10

Properties of graphite

Answer 10

3 covalent bonds
Sheets of carbon in arranged in hexagons
Held together weakly
High melting point
Conducts electricity
1 delocalised electron
Soft and slippery

Question 11

Properties of Graphene

Answer 11

One layer of graphite
Joined in hexagons
Very strong
Contains delocalised electrons so can conduct electricity

Question 12

Properties of metals

Answer 12

Solid at room temp
Good conductors of heat and electricity
Malleable

Question 13

What are nanoparticles

Answer 13

Really really tiny, have a large surface to volume ratio

Question 14

Uses of nanoparticles

Answer 14

Can be used in electric circuits
Can be added to polymer fibres to make surgical masks and deodorants
Used in cosmetics for example to improve moisturisers

Question 15

Why must magnesium chloride by molten or dissolved in water to be electrolysed

Answer 15

-so ions can move to the electrodes
-and ions carry charge

Question 16

How is magnesium produced at the negative cathode

Answer 16

-magnesium ions attracted to the electrode
-magnesium ions gain 2 electrons (reduced)

Question 17

Explain why metals can be bent or shaped

Answer 17

Layers of particles can slide easily

Question 18

Limitations of models for ionic compounds: dot and cross diagram

Answer 18

Doesn’t indicate the relative sizes of the atoms, doesn’t illustrate the 3D arrangements of the atoms and electron shells

Question 19

Limitations of models for ionic compounds: 3D construction models

Answer 19

It is not to scale, gives no information about the forces of attraction between the ions or movement of electrons

Question 20

Limitations of models for ionic compounds: 2D representations of ionic compounds

Answer 20

Does not show where the ions are located on the other layers

Question 21

In terms of electrons what helps you tell the melting boiling point of a metal

Answer 21

The greater the number of outer electrons that the metal has, the higher its melting/boiling point.

Question 22

Why is it that the greater the number of outer electrons that the metal has, the higher its melting/boiling point

Answer 22

This is due to the increased positive charge on the metal ion and the increased number of electrons that are delocalised, resulting in stronger bonding

Question 23

Describe metallic bonding in terms of electrons

Answer 23

-The electron in the outer shell of every atom is delocalised (free to move) so there is a sea of delocalised electrons
-Strong electrostatic attraction

Question 24

What is an alloy

Answer 24

Mixture of metals

Question 25

Limitations of the particle model

Answer 25

Many particles are not spherical, particles are no solid

Question 26

Why can’t ionic compounds conduct electricity

Answer 26

Their ions are held in fixed positions and cannot move

Question 27

What is the arrangement of atoms in pure metals

Answer 27

The atoms are arranged in neat layers

Question 28

Describe how atoms are arranged in an alloy

Answer 28

The smaller or bigger atoms distort the layers of atoms in pure metals

Question 29

What can Graphene be used in real life

Answer 29

Electronics and composites

Question 30

Diameter of a nano particle

Answer 30

Between 100 and 2500 nm

Question 31

Nano particles uses in real life

Answer 31

Medicine, electronics and sun cream

Question 32

Advantages of nano particles

Answer 32

Can be used as cosmetics as it is absorbed much deeper into the skin
Can be used to deliver medicines as readily absorbed

Question 33

Disadvantages of nano particles

Answer 33

Breathing in tiny particles could have a negative effect on our lungs
Might damage our cells as easily absorbed
Could accumulate in organisms over time

Question 34

What is meant by a weak acid

Answer 34

The acid is only partially ionised in aqueous solution

Question 35

Describe how metals conduct electricity

Answer 35

-metals have a delocalised electrons
-the electrons carry electrical charge
-the electrons move through the structure

Question 36

why do alloys not conduct electricity as well as pure metals

Answer 36

-in alloys different sized atoms distort the layers
-so the movement of the delocalised electron is different

Question 37

Describe what happens when a magnesium atom reacts with an oxygen atom

Answer 37

Magnesium loses electrons
Oxygen gains electrons
Two electrons are transferred
Magnesium and oxygen ions are formed

Question 38

What is the structure and bonding of diamond

Answer 38

-giant structure
-with covalent bonds
-and four bonds per carbon atom.

Question 39

Why does diamond have a high melting point

Answer 39

-strong covalent bonds
-and many covalent bonds must be broken
-so a lot of energy required to break the bonds

Question 40

What forces hold together ions with opposite charges?

Answer 40

Electrostatic

Question 41

Why does sodium oxide have a huge melting point

Answer 41

-giant structure
-with strong electrostatic forces of attraction between ions
-so large amounts of energy required to break the bonds

Question 42

Explain why an ionic compound can conduct electricity when molten

Answer 42

Ions are not free to move in solid lattice
But are to to move when it is molten

Question 43

What is the shape of a buckminsterfullerene molecule

Answer 43

Spherical

Question 44

One use of a fullerene

Answer 44

Catalysts, drug delivery

Question 45

Why would a liquid have a low boiling point

Answer 45

Weak intermolecular forces

Question 46

Why is graphite soft and slippery

Answer 46

No covalent bonds between layers
So layers can slide over each other
So graphite is soft and slippery

Question 47

Observations of potassium in water

Answer 47

-floats
-moves around
-fizzing

Question 48

Why does the reactivity of elements change as you go down group 1

Answer 48

-Reactivity increases as you go down group 1
-because the outer shell is further from the nucleus
-so there is more shielding from the nucleus
-so the atom loses an electron more easily

Question 49

Which elements are often used as a catalyst

Answer 49

Transition metals

Question 50

Why is it important to use a reaction with a high atom economy

Answer 50

Less waste

Question 51

why calcium reacts more vigorously than magnesium with hydrochloric acid of the same concentration

Answer 51

calcium has a greater number of electrons shells than magnesium, this means the distance between the positive nucleus and negative electrons is greater, making the force between them weaker. This means that it requires less energy for the calcium atoms to lose its 2 electrons in its outer shell compared to magnesium.