3.1.1 Periodicity

Question 1

First ionisation energy definition.

Answer 1

Energy required to remove one electron from each atom in one mole of gaseous atoms of an element to form one mole of gaseous 1+ ions.

Question 2

How does atomic radius affect ionisation energy?

Answer 2

Greater the distance between nucleus and outer electrons, the less the nuclear attraction.

Question 3

How does nuclear charge affect ionisation energy?

Answer 3

More protons in nucleus of an atom, greater the attraction between nucleus and outer electrons.
Therefore increased ionisation energy

Question 4

How does electron shielding affect ionisation energy?

Answer 4

Shielding effect= inner shell electrons repel outer-shell electrons
Easier to lose outer electron, ionisation energy lower

Question 5

Why would there be a large increase between 2 successive ionisation energies?

Answer 5

The second electron of the 2 is removed from an inner shell, which would take more energy.

Question 6

What is the trend of first ionisation energies down a group and explain why.

Answer 6

Decreases down a group because
-atomic radius increases
-more inner shells, shielding increases
-nuclear attraction on outer electrons decreases

Question 7

What is the trend of first ionisation energies across a period and explain why.

Answer 7

Increases because
-nuclear charge increases
-same shell, similar shielding
-nuclear attraction increases
-atomic radius decreases

Question 8

Where is the s block on the periodic table

Answer 8

Two groups on the left

Question 9

Where is the d block on the periodic table

Answer 9

Middle 10 groups

Question 10

Where is the p block on the periodic table

Answer 10

Right 6 groups

Question 11

Second ionisation energy definition

Answer 11

Energy required to remove one electron from each atom in one mole of gaseous 1+ ions of an element to form one mole of gaseous 2+ ions.

Question 12

Metallic bonding definition

Answer 12

Strong electrostatic attraction between cations and delocalised electrons

Question 13

Describe a giant metallic lattice

Answer 13

Billions of metal atoms held together by metallic bonding

Question 14

Electrical conductivity of metals

Answer 14

Metals conduct electricity as when a voltage is applied across a metal, delocalised electrons can move through the structure and carry a charge

Question 15

Melting and boiling points of metals

Answer 15

High
High temperatures needed to provide large amount of energy to overcome strong electrostatic attraction between cations and electrons

Question 16

Solubility of metals

Answer 16

Do not dissolve

Question 17

What is a giant covalent lattice

Answer 17

Billions of atoms held together by network of strong covalent bonds

Question 18

Examples of giant covalent lattices

Answer 18

Carbon (diamond, graphene, graphite)
Silicon

Question 19

Structure of diamond and silicon

Answer 19

Have 4 outer electrons that form covalent bonds with other atoms, tetrahedral structure formed

Question 20

Structure of graphene

Answer 20

Single latter of graphite, hexagonally arranged carbon atoms linked by strong covalent bonds,
Bond angles of 120, 3 covalent bonds by each carbon

Question 21

Structure of graphite

Answer 21

Parallel layers of hexagonally arranged carbon atoms, layers bonded by London forces
3 covalent bonds formed by each carbon atom, spare electron is delocalised between layers, so conducts electricity

Question 22

Melting and boiling points of giant covalent lattices

Answer 22

High due to strong covalent bonds, lots of energy needed to break bonds

Question 23

Solubility of giant covalent lattices

Answer 23

Insoluble in most solvents, covalent bonds holding together atoms in lattice are too strong to be broken

Question 24

Electrical conductivity in giant covalent lattices

Answer 24

In diamond and silicon, all outer electrons are involved in covalent bonds, no mobile charge carriers
Graphene and graphite can conduct electricity

Question 25

What’s the trend in melting points across period 2 and 3 and explanation

Answer 25

Melting point increases from group 1 to 14, sharp decrease in melting point between group 14 and 15, melting points comparatively low from group 15 to 18

Sharp decrease due to switch from giant to simple molecular substances