C7- Periodicity

Question 1

1st ionisation energy

definition

Answer 1

the energy required to remove on electron from each atom in one mole of the gaseous element to form one mole of gaseous 1+ ions

Question 2

What does nuclear attraction depend on

3 factors

Answer 2

Atomic radius

Nuclear charge

Electron shielding

Question 3

effect on 1st ionisation energy

atomic radius

Answer 3

the greater the distance between the nucleus and the outer electron, the less the nuclear attraction

Question 4

Effect on 1st ionisation energy

nuclear charge

Answer 4

The more protons the higher the nuclear charge

Question 5

Effect on 1st ionisation energy

Electron sheilding

Answer 5

Inner shells of electrons repel the outer electrons, reducing the nuclear charge experienced by the electron

Question 6

Trend of 1st ionisation energy across a period

Answer 6

General increase

The number of protons increase, so more attraction actin gone the electrons

Electrons are added to the same shield, so the outer shell is drawn inwards slightly

Same number of shell= same level of shielding but more nuclear charge

Question 7

Trend in 1st ionisation energy down a group

Answer 7

1st ionisation energy decreases

Number of electron shells increases

shielding increases

atomic radius increases

Question 8

2nd ionisation energy

Answer 8

The energy required to remove on electron from each atom in one mole of the gaseous 1+ ions to form one mole of gaseous 2 + ions

Question 9

Explain why successive ionisation energies always increase

Answer 9

As each electron is removed, the outer shell is drawn closer to the nucleus, Thus nuclear attraction is greater and more energy is needed to remove the next electron

Question 10

Periodicity

definition

Answer 10

The trend in properties that is repeated across each period

Question 11

Why does 1st ionisation energy decrease when an element has 3p4 not 3p3

Answer 11

in 3p3 each electron occupies its own orbital

in 3p4 one of these is paired, these electrons repeal each other (opposite spin) and thu s is easier to remove

Question 12

Giant metallic lattice structure

Answer 12

a lattice of positive ions in fixed positions surrounded by a sea of delocalised electrons.

Question 13

Metals

High melting and boiling points

Answer 13

The attraction between the fixed positive ions and the delocalised electrons is very strong.

So a lot of energy is needed to overcome the metallic bond and dislodge the ions from their rigid positions.

Question 14

Metals

Good electrical conductivity

Answer 14

The delocalised electrons can move freely anywhere within the lattice.

This flow of electrons carries the electrical charge through the metal.

Question 15

Metals

Malleable and ductile

Answer 15

The delocalised electrons can move it gives the solid metal a degree of ‘give’

allows the atoms of layers to slide past each other.

Question 16

Metals

Solubility

Answer 16

Insoluble

Any interactions lead to a reaction not dissolving

Question 17

Giant covalent lattice

High mp and bp

Answer 17

Many strong covalent bonds

High temperatures needed to provide the large quantities of energy needed to break strong covalent bonds

Question 18

Giant covalent lattice

Solubility

Answer 18

Covalent bonds are too strong to be broken by interactions within solvents

Question 19

Giant covalent lattice

Conductivity

Answer 19

Non conductors of electricity

All outer shell electrons are involved in covalent bonds, none are available to be mobile charge carriers

exceptions- graphite and graphene

Question 20

Periodic trends in mp

Drop in mp between giant and simple structures

Answer 20

Giant structures have strong forces to be over come, not weak

Question 21

why are metals malleable and ductile

Answer 21

because the delocalised electrons can move it gives the solid metal a degree of ‘give’ which allows the atoms of layers to slide past each other.