Periodic Table and Trends

Question 1

Define atomic radii

Answer 1

Distance from the nucleus to the boundary of the electron cloud

Question 2

Define valency

Answer 2

The valency of an atom is equal to the number of valence electrons that this atom can gain or lose during chemical reactions

Question 3

Define ionic radii

Answer 3

The distance between the centre of the nucleus and the outermost electron shell in an ion

Question 4

Define electronegativity

Answer 4

The ability of an atom to attract electrons

Question 5

Define ionisation energy

Answer 5

The amount of energy required to remove an electron to make an ion

Question 6

Describe and explain 1st ionisation energy

Answer 6

The energy required to remove one electron from each atom in one mole of gas to form one mole of 1+ gas ions

Question 7

Describe and explain successive ionisation energy

Answer 7

The energies required to remove the electrons from an atom, in sequence starting with the outermost electron

Question 8

Identify the change in oxides a period

Answer 8

• Metal oxides are basic
• Aluminium oxide is amphoteric
• Non-metal oxides are acidic

Question 9

Explain the reactivity of alkali metals [group 1]

Answer 9

These metals react easily as they only have one valence electron to lose and the reactivity increases as you go down the group because the atoms become larger and the attraction decreases

Question 10

Explain the reactivity of halogens [group 17]

Answer 10

These non-metals only have to gain one electron to achieve a full outer shell however the reactivity decreases down the group as the atomic radius increases in size, lessening the attraction for valence electrons of other atoms

Question 11

Describe metal elements

Answer 11

• Lustrous
• Dense
• Malleable
• Ductile
• Have high melting and boiling points
• Are good conductors of electricity and heat

Question 12

Describe non-metal elements

Answer 12

• Dull
• Not dense
• Brittle
• Have low melting and boiling points
• Are poor conductors of electricity and heat

Question 13

Describe metalloid elements

Answer 13

These elements have a mixture of metallic and non-metallic properties

Question 14

Describe group 1 trends in the periodic table

Answer 14

• Low melting and boiling points
• Highly reactive
• Low density
• Soft

Question 15

Describe group 2 trends in the periodic table

Answer 15

• Shiny
• Silvery in colour
• Low density
• Somewhat reactive

Question 16

Describe group 18 trends in the periodic table

Answer 16

• Colourless
• Odourless
• Inert [unreactive]
• Exist as single atoms

Question 17

Identify and describe the [5] period trends

Answer 17

• State of matter: Move from solid to gaseous across a period
• Core charge: Increases across a period and is the same down a group
• Atomic radii: Decreases across a period and increases down a group
• 1st ionisation energy: Decreases down a group and increases across a period
• Reactivity with water: Decreases down a group and increases across a period