topic 1 - atomic structure and the periodic table: the periodic table

Question 1

What is a group in the periodic table?

Answer 1

Any column in the periodic table.

Question 2

Give two properties that will be true of elements in the same group?

Answer 2

Have the same number of electrons in their outer shell which gives them similar chemical properties.

Question 3

Before the discovery of sub-atomic particles, how did scientists try to classify elements?

Answer 3

By arranging them in order of their atomic weights.

Question 4

What were the issues with early periodic tables?

Answer 4

They were incomplete and some elements were put in the wrong place if the strict rule of atomic weight was followed.

Question 5

How did Mendeleev overcome some of the problems faced with the early periodic table?

Answer 5

He left gaps for elements that he thoght hadn’t been discovered and in some places changed the order based on atomic weights.

Question 6

What did knowledge of isotopes make possible?

Answer 6

To explain why the order based on atomic weights was not always correct.

Question 7

How can you tell that an element is a metal?

Answer 7

It will react to form positive ions.

Question 8

How can you tell that an element is a non metal?

Answer 8

It will not react to form positive ions.

Question 9

Why do the the alkali metals have characteristic properties?

Answer 9

Because of the single electron in their outer shell.

Question 10

How does lithium react with oxygen?

Answer 10

Lithium burns with a strongly red-tinged flame if heated in air. It reacts with oxygen in the air to give white lithium oxide.

Question 11

How does lithium react with chlorine?

Answer 11

It fizzes steadily and slowly becomes smaller until it disappears.

Question 12

How does sodium react with water?

Answer 12

Sodium metal reacts rapidly with water to form a colourless basic solution of sodium hydroxide (NaOH) and hydrogen gas (H2).

Question 13

How does sodium react with oxygen?

Answer 13

Generates a lot of heat energy and light.

Question 14

How does sodium react with chlorine?

Answer 14

Produces a bright yellow light and a lot of heat energy.

Question 15

What are the group 0 elements called?

Answer 15

The noble gases.

Question 16

Are the group 0 elements reactive or unreactive?

Answer 16

Unreactive.

Question 17

Why do group 0 elements not easily form molecules?

Answer 17

Because their atoms have stable arrangements of electrons.

Question 18

How many electrons do the noble gases have in their outer shell, which element is the exception to this and how many electons oes it have?

Answer 18

8, apart from helium, which has 2.

Question 19

Do the boiling points of the noble gases increase or decrease going down the group?

Answer 19

Increase.

Question 20

Does the reactivity of the alkali metals increase or decrease going down the group?

Answer 20

Increase.

Question 21

What are the group 1 elements called?

Answer 21

The alkali metals.

Question 22

What are the group 7 elements called?

Answer 22

The halogens.

Question 23

Are the halogens metals or non-metals?

Answer 23

Non-metals.

Question 24

Are halogen molecules monotomic or diatomic?

Answer 24

Diatomic (each molecule is made up of a pair of atoms).

Question 25

What do the halogens produce when reacted with metals?

Answer 25

Salts.

Question 26

What happens when chlorine reacts with iron wool?

Answer 26

Hot iron wool burns vigorously to produce iron (III) chloride.

Question 27

What happens when chlorine reacts with halogen?

Answer 27

Explodes with a flame or in sunlight, forming hydrogen chloride.

Question 28

What happens with bromine reacts with iron wool?

Answer 28

Hot iron wool burns quickly to produce red-brown iron (III) bromide.

Question 29

What happens when bromine reacts with hydrogen?

Answer 29

Vigorous reaction with burning hydrogen, forming hydrogen bromide.

Question 30

What happens when iodine reacts with iron wool?

Answer 30

Hot iron wool reacts slowly in iodine vapour to produce grey iron (II) iodide.

Question 31

What happens when iodine reacts with hydrogen?

Answer 31

Very slow reaction when heated strongly, forming some hydrogen iodide.

Question 32

As you go further down group 7, do the relative molecular masses, boiling points and melting points get higher or lower?

Answer 32

Higher.

Question 33

Does the reactivity of the halogens increase or decreas going down the group?

Answer 33

Decrease.

Question 34

What can a more reactive halogen displace a less reactive halogen from?

Answer 34

An aqueous solution of its salt.