C3.1 The periodic table

Question 1

Who was the first to arrange a periodic table?

Answer 1

Newlands

Question 2

Why was Newlands’ work ignored?

Answer 2

Because he left no gaps for undiscovered elements

Question 3

Who was the second person to arrange the elements into a periodic table?

Answer 3

Mendeleev

Question 4

How did Mendeleev arrange his periodic table?

Answer 4

He put the elements in order of atomic mass, but he left gaps in order to keep the elements with similar properties in the same vertical columns (groups)

Question 5

What did the gaps in Mendeleev’s table predict?

Answer 5

The properties of the undiscovered elements

Question 6

Elements with the same properties were in the same…

Answer 6

Columns, known as groups

Question 7

Why is it called the periodic table?

Answer 7

Because similar properties occur at regular intervals

Question 8

In the early periodic table some elements were placed in inappropriate groups because…

Answer 8

Newlands did not leave gaps in his table for undiscovered elements

Question 9

What was discovered in the 20th century that caused a change in the arrangement of the periodic table?

Answer 9

Protons, neutrons and electrons

Question 10

How was the periodic table rearranged after this discovery?

Answer 10

The periodic table was rearranged in order of atomic (proton) numbers. Then all the elements were placed in the appropriate groups

Question 11

How else can the modern periodic table be seen as arranged by?

Answer 11

The electronic structures of the elements, elements in the same group have the same number of electrons in their outer shell

Question 12

What is the number of each group also equal to?

Answer 12

The number of electrons in their outer shell

Question 13

What are the elements in Group 1 known as?

Answer 13

The alkali metals

Question 14

Alkali metals have a low…

Answer 14

Density

Question 15

Alkali metals react with non-metals to form…

Answer 15

Ionic compounds in which the metal ion carries a charge of +1

Question 16

What ionic compounds are formed from alkali metals and non-metals?

Answer 16

White solids that dissolve in water to form a colourless solution

Question 17

When alkali metals react with water they…

Answer 17

Release hydrogen

Question 18

Alkali metals form…

Answer 18

Hydroxides that dissolve in water to give alkaline solutions

Question 19

In Group 1, the further down the group an element is, the more…

Answer 19

Reactive it is

Question 20

In Group 1, the further down the group an element is, the lower…

Answer 20

Its melting and boiling point

Question 21

Why, in Group 1, are the elements further down more reactive?

Answer 21

Because they are much bigger, therefore meaning the outer shell is much further from the nucleus. This means the forces of attraction holding them together are much weaker, allowing the outer electron to be lost easily

Question 22

Compared with elements in Group 1, transition elements have higher…

Answer 22

Melting and boiling points and higher densities

Question 23

Compared with elements in Group 1, the transition elements are…

Answer 23

Stronger and harder

Question 24

Compared with elements in Group 1, the transition elements are much less…

Answer 24

Reactive and therefore do not react as vigorously with water or oxygen

Question 25

What do many transition elements form?

Answer 25

Colourful compounds

Question 26

Many transition elements have ions...

Answer 26

With different charges

Question 27

What are many transition elements useful as?

Answer 27

Catalysts

Question 28

What are the elements of Group 7 known as?

Answer 28

The halogens

Question 29

What do the halogens react with metals to form?

Answer 29

Ionic compounds in which the halide ion carries a -1 charge

Question 30

In Group 7, the further down the group an element is, the less

Answer 30

Reactive the element is

Question 31

In Group 7, the further down the group an element is, the higher...

Answer 31

Its melting and boiling point

Question 32

Why in Group 7, are the elements further down the group less reactive?

Answer 32

Because the elements further down are bigger and the outer shell further away from the nucleus the forces of attraction pulling towards the nucleus are weaker, making it more difficult to gain an electron

Question 33

What can a more reactive halogen do to a less reactive halogen?

Answer 33

A more reactive halogen can displace a less reactive halogen form an aqueous solution of its salt

Question 34

What can the trends in reactivity within the groups be explained by?

Answer 34

The higher the energy level, the further out the outer shell is from the nucleus, the more easily electrons are lost and the less easily electrons are gained