Chapters 4, 11 and 12-The Periodic Table, Alkali Metals and Halogens

Question 1

In what order is the periodic table arranged?

Answer 1

In order of atomic number

Question 2

Where are metals located in the Periodic Table?

Answer 2

On the left-hand-side

Question 3

Where are non-metals located in the Periodic Table?

Answer 3

On the right-hand-side

Question 4

Where does the stepped line which separates the metals and non-metals start?

Answer 4

It starts below boron.

Question 5

Do metals conduct electricity?

Answer 5

Yes, they are good conductors of electricity.

Question 6

Do non-metals conduct electricity?

Answer 6

No, they are poor conductors of electricity (except graphite and silicon).

Question 7

Do metals form acidic or basic oxides?

Answer 7

They form basic oxides (if they are soluble in water, they dissolve to form solutions with a pH greater than 7).

Question 8

Do non-metals form acidic or basic oxides?

Answer 8

They form acidic oxides (if they are soluble in water, they dissolve to form solutions with a pH less than 7).

Question 9

Do metals react with acids or bases to form salts?

Answer 9

They react with acids to form salts.

Question 10

Do non-metals react with acids or bases to form salts?

Answer 10

They react with bases to form salts.

Question 11

What does the group number tell us?

Answer 11

The number of electrons in the outer shell

Question 12

What does the period number tell us?

Answer 12

The number of shells occupied

Question 13

Why do elements in the same group have similar chemical properties?

Answer 13

They have the same number of electrons in their outer shell; the chemical properties depend on the number of electrons in the outer shell.

Question 14

What are the elements in group 0 called?

Answer 14

Noble gases

Question 15

How many electrons do the noble gases have in their outer shell?

Answer 15

They have 8 electrons in their outer shell (apart from helium, which has 2).

Question 16

Why are the noble gases unreactive?

Answer 16

They do not need to lose, gain or share electrons in a chemical reaction to become stable (and their outer shell is full).

Question 17

What are the elements in group 1 called?

Answer 17

The alkali metals

Question 18

Do the alkali metals have low or high melting and boiling points and do they increase or decrease down the group?

Answer 18

They have very low melting and boiling points for metals and they decrease down the group.

Question 19

Do the alkali metals have low or high densities and do they increase or decrease down the group?

Answer 19

They have low densities which increase down the group, but not regularly. Lithium, sodium and potassium are all less dense than water and so float on it.

Question 20

Are the alkali metals hard or soft and do they become harder or softer down the group?

Answer 20

They are very soft and can be easily cut with a knife, becoming softer as you go down the group.

Question 21

Are the alkali metals shiny?

Answer 21

They are shiny and silver when freshly cut but tarnish very quickly on exposure to air.

Question 22

Why are lithium, sodium and potassium stored under oil?

Answer 22

To stop them reacting with oxygen or water vapour in the air.

Question 23

Why mustn’t you touch any of the alkali metals with your bare hands?

Answer 23

There could be enough sweat on your skin to give a reaction, producing lots of heat and a very corrosive metal hydroxide.

Question 24

Give four general observations when an alkali metal reacts with water.

Answer 24

It moves around on the surface of the water (hydrogen not given off symmetrically around the metal).
It fizzes/effervesces(hydrogen gas produced).
It floats.
It gets smaller and eventually disappears.

Question 25

What is a safety point to be noted for when alkali metals react with water?

Answer 25

Use a safety screen as hydrogen gas is explosive.

Question 26

What do alkali metals form when they react with water?

Answer 26

They all react with water to form a solution of metal hydroxide and hydrogen gas.

Question 27

How do alkali metals react with air?

Answer 27

They tarnish when exposed to air as they react with oxygen in the air to form an oxide.

Question 28

Out of lithium, sodium and potassium, which tarnishes the fastest and which tarnishes the slowest?

Answer 28

Potassium tarnishes the fastest and lithium tarnishes the slowest.

Question 29

What coloured flames do lithium, sodium and potassium burn with?

Answer 29

Lithium burns with a red flame to form lithium oxide, sodium burns with a yellow/orange flame to form sodium oxide and potassium burns with a lilac flame to form potassium oxide.

Question 30

What does the metal hydroxide dissolve in water to produce?

Answer 30

An alkaline solution which turns Universal Indicator (UI) purple.

Question 31

Does reactivity increase or decrease down group 1?

Answer 31

It increases; the reactions get faster and more vigorous down the group.

Question 32

Why does reactivity increase down group 1?

Answer 32

The number of shells increases down the group so the outer electron is further away from the positive nucleus and so is less strongly attracted to it; it is easier to be lost which makes the atom more reactive.

Question 33

Predict some properties of francium.

Answer 33

It is very soft. It has a lower melting and boiling point than Caesium; it will be around room temperature. It is more dense than Caesium. It reacts explosively with water to produce francium hydroxide and hydrogen.

Question 34

What colour is chlorine and what is its state at room temperature?

Answer 34

Chlorine is a green gas at room temperature.

Question 35

What colour is bromine and what is its state at room temperature?

Answer 35

Bromine is a red-brown liquid at room temperature but forms an orange vapour (low boiling point).

Question 36

What colour is iodine and what is its state at room temperature?

Answer 36

Iodine is a dark grey solid at room temperature but forms a purple vapour (sublimes).

Question 37

Predict the colour of fluorine and its state at room temperature.

Answer 37

Fluorine is a yellow gas at room temperature.

Question 38

Predict the colour of astatine and its state at room temperature.

Answer 38

Astatine is a black solid at room temperature.

Question 39

What are the elements in group 7 called?

Answer 39

The halogens

Question 40

Does reactivity increase or decrease down the group?

Answer 40

Reactivity decreases down group 7 e.g. bromine is less reactive than chlorine.

Question 41

Why does reactivity decrease down group 7?

Answer 41

The number of shells increases down the group, so the electron being gained is further away from the positive nucleus and so is less strongly attracted to it; it is harder to gain an electron which makes the atom less reactive.

Question 42

What happens in a displacement reaction?

Answer 42

A more reactive halogen displaces a less reactive halogen from a solution of one of its salts.

Question 43

What coloured solution is seen if bromine is formed in a displacement reaction?

Answer 43

The solution becomes orange as bromine is formed.

Question 44

What coloured solution is seen if iodine is formed in a displacement reaction?

Answer 44

The solution becomes brown (orange if very dilute) as iodine is formed.

Question 45

What is a safety point to be noted when handling halogens?

Answer 45

The halogens have extremely poisonous vapours and so have to be handled in a fume cupboard/fumehood.

Question 46

In a displacement reaction between chlorine and potassium bromide, what has been reduced and what has been oxidised?

Answer 46

In this reaction, the chlorine has been reduced as it gains electrons and the bromide ions have been oxidised as they have lost electrons. The chlorine is the oxidising agent.