Topic 1b - The Periodic Table

Question 1

How are elements organised in the periodic table?

Answer 1

The elements in the periodic table are arranged in order of atomic (proton) number and so that elements with similar properties are in columns, known as groups.

Question 2

Why is it called the periodic table?

Answer 2

The table is called a periodic table because similar properties occur at regular intervals.

Question 3

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

Answer 3

Elements in the same group in the periodic table have the same number of electrons in their outer shell (outer electrons) and this gives them similar chemical properties.

Question 4

How did scientists attempt to classify elements before the discovery of protons, neutrons and electrons?

Answer 4

Before the discovery of protons, neutrons and electrons, scientists attempted to classify the elements by arranging them in order of their atomic weights + physical/chemical properties.

Question 5

How did John Newland arrange his periodic table?

Answer 5

By atomic mass but there were many mistakes and inconsistencies.

Question 6

What was wrong with early periodic tables?

Answer 6

The early periodic tables were incomplete and some elements were placed in inappropriate groups if the strict order of atomic weights was followed.

Question 7

How did Dimitri Mendeleev overcome some of the problems of the early periodic table and when?

Answer 7

• In 1869, Dimitri Mendeleev overcame some of the problems of the early periodic tables by taking 57 known elements + arranging them into his Table of Elements, leaving various gaps.
• He put the elements, mainly in order of atomic weight but did switch the order of some elements if the properties mean it should be changed.
• Gaps were left in the table to make sure elements with similar properties remained in the same groups. He was able to predict some new elements, which later on proved to be correct.

Question 8

When were isotopes discovered and how did this impact Mendeleev’s periodic table?

Answer 8

• Early 20th century
• Confirmed Mendeleev was correct not to place elements in a strict order of atomic weight but to also take into account their properties.
• Because isotopes of the same element have different masses but the same chemical properties so occupy the same position on the periodic table.

Question 9

What are metals?

Answer 9

Elements that react to form positive ions are metals. The majority of elements are metals.

Question 10

What are non-metals?

Answer 10

Elements that do not form positive ions when they react are non-metals. They either form negative ions, or they covalently bond with other non-metals.

Question 11

Where are metals found on the periodic table?

Answer 11

Metals are found to the left and towards the bottom of the periodic table.

Question 12

Where are non-metals found on the periodic table?

Answer 12

Non-metals are found towards the right and top of the periodic table.

Question 13

What are the elements in Group 1 of the periodic table?

Answer 13

The elements in Group 1 of the periodic table are known as the alkali metals and have characteristic properties because of the single electron in their outer shell.

Question 14

What happens to the reactivity of elements in group 1 as you go down the group?

Answer 14

In Group 1, the reactivity of the elements increases going down the group, because outer shells are further away from the nucleus - have a stronger negative charge.

Question 15

What happens to the Ar as you go down the group 1 elements?

Answer 15

Relative Atomic Mass increases down the group.

Question 16

How do the group 1 metals react with nonmetals?

Answer 16

Form ionic compounds

Question 17

How do the group 1 metals react with water?

Answer 17

alkali metal + water => metal hydroxide + hydrogen

Question 18

How do the group 1 metals react when heated in chlorine gas?

Answer 18

• React most vigorously when heated in chlorine gas
• alkali metal + chlorine => metal chloride

Question 19

How do the group 1 metals react with oxygen?

Answer 19

Form metal oxide. Different types of oxides are formed depending on the metal.

Question 20

What are the Group 7 elements of the periodic table?

Answer 20

The elements in Group 7 of the periodic table are known as the halogens and have similar reactions because they all have seven electrons in their outer shell. The halogens are non-metals and consist of molecules made of pairs of atoms.

Question 21

What increases as you go down the Group 7 elements?

Answer 21

In Group 7, the further down the group an element is the higher its relative molecular mass, melting point and boiling point.

Question 22

What decreases as you go down the Group 7 elements?

Answer 22

In Group 7, the reactivity of the elements decreases going down the group because they react by gaining an electron and the further away the outer shell is from the nucleus, the less likely it will attract electrons.

Question 23

What can a more reactive halogen displace?

Answer 23

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

Question 24

How do Group 7 elements react with other non-metals?

Answer 24

Covalently bond with other non-metals

Question 25

How do Group 7 elements react with metals?

Answer 25

Form 1- ions with metals

Question 26

What is fluorine?

Answer 26

A poisonous, yellow gas

Question 27

What is chlorine?

Answer 27

A poisonous, dense, green gas

Question 28

What is bromine?

Answer 28

Dense, poisonous red/brown volatile liquid OR orange vapour

Question 29

What is iodine?

Answer 29

Poisonous, dark grey crystalline solid OR purple vapour

Question 30

What are the Group 0/8 elements?

Answer 30

The elements in Group 0 of the periodic table are called the noble gases.

Question 31

Are the Group 0/8 elements reactive and why?

Answer 31

They are unreactive and do not easily form molecules because their atoms have stable arrangements of electrons.

Question 32

What are the shells like in Group 0/8 elements?

Answer 32

The noble gases have eight electrons in their outer shell, except for helium, which has only two electrons.

Question 33

What increases as you go down the Group 0/8 elements?

Answer 33

The boiling points of the noble gases increase with increasing relative atomic mass (going down the group).

Question 34

What can you use trends within the Group 0/8 elements for?

Answer 34

To predict other boiling points, and states of elements at different temperatures within the group.

Question 35

What are the transition metals?

Answer 35

The transition elements are metals with similar properties which are different from those of the elements in Group 1.

Question 36

What are the features of transition metals? (4)

Answer 36

• Good conductors of heat + electricity
• Dense
• Strong
• Shiny

Question 37

How do the transition metals compare to the group 1 alkali metals?

Answer 37

• Transition metals = less reactive than group 1 metals
• Transition metals = much denser, stronger + harder than the group 1 metals
• Transition metals have higher m.p. and b.p. than the group 1 metals

Question 38

What can most transition metals form?

Answer 38

Ions with different charges

Question 39

What are transition metal compounds like?

Answer 39

Very colourful compounds

Question 40

What do transition metals and their compounds all make? (not literally make, more so can be used as)

Answer 40

Good catalysts