C4 Knowledge organiser

Question 1

Atom

Answer 1

Smallest possible piece of an element. Has a radius of 0.1nm

Question 2

Ion

Answer 2

A charged particle which can be positive or negative

Question 3

Electron

Answer 3

A negatively charged particle found in energy levels around the nucleus. Has a relative mass of 0

Question 4

Ionic Bonding

Answer 4

Occurs between a metal and non-metal element where the metal atom lodes electrons to a non-metal atom to form ions

Question 5

Chemical Formula

Answer 5

Tells you which atoms and how many of them are present

Question 6

Oxidation

Answer 6

A reaction where oxygen is added

Question 7

Reduction

Answer 7

A reaction where oxygen is removed

Question 8

Reactivity series

Answer 8

A table of elements in order of reactivity

Question 9

Displacement

Answer 9

where a more reactive element displaces a less reactive element from its compound

Question 10

Ore

Answer 10

An ore is a rock that contains enough of a metal compound in it to be worth extracting

Question 11

Native metal

Answer 11

an unreactive metal that is found on its own in the ground

Question 12

How can metals be placed in order of their reactivity

Answer 12

Add the metals to water or acid and see which ones react the most vigorously

Question 13

Why is Platinum found in the Earth’s crust as the metal itself

Answer 13

It is unreactive

Question 14

How are metals less reactive than carbon extracted from their ore

Answer 14

Reduction with carbon

Question 15

Define oxidation in terms of electrons

Answer 15

Oxidation is the loss of electrons

Question 16

Define reduction in terms of electrons

Answer 16

Reduction is the gain of electrons

Question 17

State 3 common acids and give their formulae

Answer 17

HCL hydrochloric
Sulphuric h2so4
Nitric HNO3

Question 18

Define an acid in terms of ions

Answer 18

An acid releases H+ ions in solution

Question 19

How do you measure pH

Answer 19

With an indicator or a pH meter

Question 20

what is a base

Answer 20

A metal oxide, hydroxide or carbonate that will react with an acid

Question 21

Acids

Answer 21

A substance that has a pH less than 7

Question 22

Alkalis

Answer 22

A soluble base that has a pH higher than 7

Question 23

Neutral solution

Answer 23

A solution that has a pH of exactly 7

Question 24

A salt

Answer 24

A salt is a compound where the hydrogen from an acid has been replaced with a metal

Question 25

Neutralization

Answer 25

The reaction between an acid and a base to form a salt plus water

Question 26

Electrolysis

Answer 26

A separation technique in which a compound is split into its elements using electricity

Question 27

Anode

Answer 27

The positive electrode, made from carbon

Question 28

Cathode

Answer 28

The negative electrode, made from carbon

Question 29

Electrolyte

Answer 29

The substance that is getting split by electricity. Has to be either molten or an aqueous solution

Question 30

Cryolite

Answer 30

A substance added to a aluminium oxide to lower its melting point

Question 31

Cation

Answer 31

A positive ion that is attracted to the cathode in electrolysis

Question 32

Anion

Answer 32

A negative ion that is attracted to the anode in electrolysis

Question 33

Which ions are always present in a solution of an alkali

Answer 33

Hydroxide ions OH-

Question 34

What types of salts are formed by the main 3 acids

Answer 34

``` HYdrochloric = Chlorides Sulphuric = Sulphates Nitric = Nitrates ```

Question 35

Which ions always react in a neutralisation reaction

Answer 35

H+ and OH-

Question 36

How does pH depend on the concentration of H+ in a solution

Answer 36

As the concentration of H+ increases by a factor of ten, the pH decreases by one

Question 37

What are the main disadvantages of using electrolysis to extract metals

Answer 37

Required a large amount of energy to melt the compounds and to produce electricity

Question 38

Why is aluminium oxide mixed with cryolite

Answer 38

To lower the melting point

Question 39

In the electrolysis of an ionic solution, when will oxygen be produces

Answer 39

If the metal is not a halogen

Question 40

What happens to water molecules in the electrolysis of solutions

Answer 40

They break up into hydrogen and hydroxide ions