C3.1 The Periodic Table

Question 1

How were elements arranged and why?

Answer 1

In relative atomic mass, because scientists were not aware of atomic structure, so there was no such thing as atomic number

Question 2

How did Newlands arrange his periodic table?

Answer 2

In order of atomic mass

Question 3

What was Newlands’ Law of Octaves?

Answer 3

Every eighth element in his periodic table had similar properties

Question 4

How did Newlands’ record his Octaves?

Answer 4

In rows of 7, elements with similar properties were in columns known as groups

Question 5

Why was Newlands’ Periodic table criticised?

Answer 5

Some of the elements which had similar properties, didn’t, e.g. carbon and titanium
Metals and Non-Metals were in the same group
New elements discovered, didn’t fit his table

Question 6

What did Mendeleev do that was different from Newlands?

Answer 6

He left gaps for undiscovered elements - these gaps predicted the properties of the elements

Question 7

What did Mendeleev do that was similar to Newlands’ work?

Answer 7

Ordered in order of atomic mass and elements with similar properties were in columns (groups)

Question 8

How is the modern periodic table arranged?

Answer 8

In order of atomic number

Question 9

Why is the periodic table useful?

Answer 9

Helped to predict properties of undiscovered elements, useful summary of the structure of atoms

Question 10

What do elements in the same group (column) have?

Answer 10

Apart from the transition metals, elements in the same group have the same number of electrons in their outer shells

Question 11

What do elements in the same period (row) have?

Answer 11

Elements in the same group have the same amount of electron shells

Question 12

What is shielding?

Answer 12

When inner electron shells reduce the attraction between the protons in the nucleus and outer electrons

Question 13

How does shielding affect reactions?

Answer 13

More electron shells means it is easier to lose electrons and harder to gain electrons

Question 14

How does the reactivity change in group 1 and why?

Answer 14

It increases as you go down the group - Group 1 metals react by losing an electron, so the more electron shells, the easier it is to lose an electron

Question 15

How does the reactivity change in group 7 and why?

Answer 15

It decreases as you go down the group - Group 7 metals react by gaining an electron, so the more electron shells, the harder it is to gain an electron

Question 16

What are the properties of the alkali metals (group 1 metals)?

Answer 16

Silvery solids that burn the skin, have a low density and have one electron in their outer shells

Question 17

How does the melting and boiling points change as you go down group 1?

Answer 17

As you go down the group, the melting and boiling points decrease

Question 18

How do the alkali metals react with non-metals?

Answer 18

They react to form ionic compounds

Question 19

What are the compounds like when alkali metals react with non-metals?

Answer 19

White solids that dissolve in water to form colourless solutions

Question 20

What is the word equation for the alkali metals with water?

Answer 20

Alkali metal + water ==> metal hydroxide + hydrogen

Question 21

What is the reaction of water and the group 1 metals like?

Answer 21

Lithium, sodium and potassium float and move around the surface of the water fizzing furiously

Question 22

What happens when you react the elements below potassium with water?

Answer 22

They react explosively

Question 23

What happens to the solution when the alkali metals react with water?

Answer 23

The hydroxides produced dissolve in the water to give an alkaline solution

Question 24

What is the test for Hydrogen?

Answer 24

The Squeaky Pop test - A lit splint is placed near where the reactants are reacting, if hydrogen is present a squeaky pop will be heard

Question 25

What is the coloured vapour of Fluorine?

Answer 25

A poisonous yellow gas

Question 26

What is the coloured vapour of Chlorine?

Answer 26

A poisonous dense green gas

Question 27

What is the coloured vapour of Bromine?

Answer 27

A dense, poisonous, red-brown volatile liquid

Question 28

What is the coloured vapour of Iodine?

Answer 28

A dark grey crystalline solid or a purple vapour

Question 29

How do the Halogen (group 7) elements presented?

Answer 29

They exist as molecules which are pairs of atoms

Question 30

How does the melting point and boiling point change as you go down Group 7?

Answer 30

As you go down the group, the melting and boiling points of the elements increase

Question 31

How do the Halogens react?

Answer 31

They need to gain an electron forming 1- ions known as the halide ions

Question 32

What happens when the Halogens react with metals?

Answer 32

They gain an electron forming ionic compounds

Question 33

What happens if a more reactive halogen is added to a solution containing a less reactive halogen?

Answer 33

The more reactive halogen displaces the less reactive halogen

Question 34

What are the properties of the transition metals?

Answer 34

They’re: Good conductors of heat and electricity, and are very dense, strong and shiny

Question 35

What’s different between the transition metals and the alkali metals?

Answer 35

The T’ metals are less reactive than the A’ metals,
T’ metals are much denser, stronger and harder,
T’ metals have higher melting points than the A’ metals

Question 36

Name some transition metals which can form ions with different charges

Answer 36

Iron (Fe): Fe2+ or Fe3+ ions
Copper (Cu): Cu+ or Cu2+ ions
Chromium (Cr): Cr2+ or Cr3+ ions

Question 37

What colour are compounds containing Fe2+?

Answer 37

Green

Question 38

What colour are compounds containing Fe3+?

Answer 38

Yellow

Question 39

Where are transition metal compounds found?

Answer 39

The colours in gemstones; like blue sapphires and green emeralds, and the colours in pottery glazes are due to transition metals

Question 40

What can the transition metals be used as?

Answer 40

Catalysts, e.g. Iron in the Haber process