Section 4

Question 1

how do alkali metals react when they are put in water?

Answer 1

they all react vigorously (in a similar way)

Question 2

what does the reaction between alkali metals and water produce?

Answer 2

a metal hydroxide solution (which is alkaline)

Question 3

why are group 1 elements known as the alkali metals?

Answer 3

because they form an alkaline metal hydroxide solution

Question 4

what does the reaction of alkali metals with water also produce?

Answer 4

hydrogen - this is why you can see fizzing

Question 5

which elements in group 1 are most reactive?

Answer 5

group 1 elements become more reactive down the group as the atomic number increases

Question 6

how can you tell that alkali metals become more reactive?

Answer 6

the rate of reaction with water increases

Question 7

name 3 alkali metals.

Answer 7

Lithium (Li), Sodium (Na), Potassium (Ka), Rubidium (Rb), Caesium (Cs), Francium (Fr)

Question 8

what are the properties of alkali metals?

Answer 8

• soft
• low density
• low melting point

Question 9

what are the properties down the group of alkali metals?

Answer 9

• they are more reactive
• their boiling point decreases

Question 10

why are alkali metals so reactive?

Answer 10

• they all have one electron in their outer shell
• further down the group the radium of the atoms get bigger
• the outer shell is further away from the positive nucleus
• positive nucleus holds outermost electron in place
• the distance weakens the attractive force

Question 11

how are group 7 elements called?

Answer 11

halogens

Question 12

as the atomic number of halogens increases…

Answer 12

• the less reactive
• the elements have a darker colour
• higher boiling point

Question 13

which halogens are most reactive?

Answer 13

higher up group 7 elements are more reactive

Question 14

whats the colour and physical state at room temperature of chlorine?

Answer 14

• green
• gas

Question 15

whats the colour and physical state at room temperature of bromine?

Answer 15

• red-brown
• liquid

Question 16

whats the colour and physical state at room temperature of iodine?

Answer 16

• dark grey
• solid

Question 17

describe the boiling points of halogens.

Answer 17

the further down (the higher the atomic number) the higher the boiling point of the element

Question 18

why are halogens further down less reactive?

Answer 18

they have more shells and the outer electrons are therefore further away from the positive nucleus meaning that the forces of attraction are weaker and its more difficult to gain another electron

Question 19

which gases are found in the atmosphere?

Answer 19

• carbon dioxide
• oxygen
• argon
• nitrogen

Question 20

how much argon is found in the atmosphere?

Answer 20

1%

Question 21

how much oxygen is found in the atmosphere?

Answer 21

21%

Question 22

how much nitrogen is found in the atmosphere?

Answer 22

78%

Question 23

how much carbon dioxide is found in the atmosphere?

Answer 23

0.04%

Question 24

what kind of gas is carbon dioxide?

Answer 24

a greenhouse gas

Question 25

exothermic reaction

Answer 25

chemical reactions which give out heat energy to the surrounding

Question 26

what is the most common element in the air?

Answer 26

nitrogen

Question 27

name the type of reaction that occurs when an acid reacts with an alkali

Answer 27

neutralisation

Question 28

what does an acid + metal oxide produce?

Answer 28

salt + water

Question 29

what does an acid + metal hydroxide produce?

Answer 29

salt + water

Question 30

what does an acid + ammonia produce?

Answer 30

ammonium salt

Question 31

when does iron corrode?

Answer 31

iron rusts when it is in contact with oxygen and water

Question 32

what type of reaction takes place when iron corrodes?

Answer 32

oxidation reaction iron gains oxygen to form iron (III) oxide

Question 33

what is the word equation for the reaction in which rust forms?

Answer 33

iron + oxygen + water = hydrated iron (III) oxide (rust)

Question 34

what is a problem with rust?

Answer 34

it is a soft crumbly solid that soon flakes off to leave more iron available to rust again

Question 35

what are the methods to prevent rusting?

Answer 35

barrier methods sacrificial method galvanising

Question 36

alkali metals and oxygen react to form what?

Answer 36

metal oxdies

Question 37

lithium and oxygen form

Answer 37

Question 38

sodium and oxygen form

Answer 38

Question 39

potassium and oxygen form

Answer 39

Question 40

boiling point of chlorine

Answer 40

-34°C

Question 41

boiling point of bromine

Answer 41

59°C

Question 42

boiling point of iodine

Answer 42

185°C

Question 43

describe the colour change of halogens down the group

Answer 43

the colours of halogens get darker

Question 44

describe the boiling points of halogens

Answer 44

the boiling point of halogens increase down the group

Question 45

displacement reactions

Answer 45

more reactive halogens will displace less reactive ones

Question 46

what happens if you add chlorine water to potassium iodide?

Answer 46

chlorine will react with potassium to form potassium chloride

Question 47

burning magnesium

Answer 47

- burns with bright white flame - magnesium oxide forms (white powder) - magnesium oxide is alkaline when dissolved in water

Question 48

burning hydrogen

Answer 48

- burns very easily / can be explosive - almost invisible pale blue flame - product is water vapour - squeaky pop

Question 49

burning sulfur

Answer 49

- pale blue flame - produces sulfur dioxide - acidic when dissolved in water

Question 50

thermal decomposition

Answer 50

break down of a substance into simpler substances when heated

Question 51

what is produces when you heat a metal carbonate?

Answer 51

carbon dioxide and a metal oxide

Question 52

colour of copper (II) carbonate

Answer 52

green

Question 53

colour of copper (II) oxide

Answer 53

black

Question 54

what happens if you heat copper (II) carbonate?

Answer 54

the green powder will decompose to form carbon dioxide and copper (II) oxide

Question 55

thermal decomposition of copper (II) carbonate

Answer 55

- heat copper (II) carbonate then collect the gas that is given off in a test tube - the collected gas can then be tested to see if it is CO2 using the limewater test

Question 56

what are three greenhouse gases ?

Answer 56

- water vapour - carbon dioxide - methane

Question 57

what do greenhouse gases do?

Answer 57

they absorb most of the heat that would be radiated out into space, and re-radiate it in all directions - including back towards the earth

Question 58

what human activities increase the amount of CO2 in the atmosphere?

Answer 58

DEFORESTATION: fewer trees means less CO2 is removed from the atmosphere via photosynthesis BURNING FOSSIL FUELS: carbon that was in these fuels is being released as CO2

Question 59

what can climate change result in ?

Answer 59

flooding, sea level rise

Question 60

what do some metals produce when reacting with acids?

Answer 60

salt + hydrogen

Question 61

how metals react with acids tells you about their reactivity

Answer 61

the more reactive the metal, the faster the reaction will go

Question 62

practical to investigate the difference in reactivity

Answer 62

1) set up 3 boiling tubes and fill them with equal volumes of dilute hydrochloric acid or sulfuric acid 2) place pieces of magnesium, zinc, iron in separate test tubes (same size and shape) 3) speed of reaction is indicated by rate at which bubbles of hydrogen are formed 4) hydrogen is confirmed by burning splint test (squeaky pop)

Question 63

reactivity series

Answer 63

potassium sodium lithium calcium magnesium aluminium zinc iron copper silver gold

Question 64

metals and acids react to produce what?

Answer 64

salt + hydrogen

Question 65

give an example of a metal and an acid reacting

Answer 65

Na + HCl = NaCl + H