Chapter 7

Question 1

Periodicity?

Answer 1

Repeating trend in properties of the elements across a period

Question 2

1st ionisation energy?

Answer 2

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 3

Factors affecting ionisation energy

Answer 3

Atomic radius - the greater the distance between nucleus and outer electrons, the less nuclear attraction

Nuclear charge - the more protons in the nucleus, the greater the attraction between nucleus and valence electrons

Electrons shielding - electrons repel since they are negatively charged. Inner shell electrons repel outer shell electrons and the repulsion is called the shielding effect. This reduces the attraction between nucleus and outer electrons

Question 4

Second ionisation energy?

Answer 4

Energy required to remove one electrons from each ion in one mole of gaseous +1 ions of an element to form one mole of gaseous 2+ ions

Question 5

Successive ionisation energies allow predictions to be made about…

Answer 5

Number of electrons in outer shell
Group of the element in the periodic table
Identity of the element

Question 6

4 properties of periodicity?

Answer 6

Electron configuration
Ionisation energy
Structure
Melting points

Question 7

Group 1 name?

Answer 7

Alkali metals

Question 8

Group 2 names?

Answer 8

Alkaline earth metals

Question 9

Why does ionisation energy decrease down the group

Answer 9

Although nuclear charge increases…
Atomic radius increases
More inner shells so shielding increases
Nuclear attraction on outer electrons decreases
1st ionisation energy decreases

Question 10

Why does ionisation energy increase across a period?

Answer 10

Nuclear charge increases
Same shell: similar shielding
Nuclear attraction increases
Atomic radius decreases
1st ionisation energy increases

Question 11

Why does the ionisation energy fall from beryllium to boron

Answer 11

It marks the start of filling of the 2p sub-shell
2p sub shell has a higher energy than 2s sub shell
The 2p electron is easier to remove in boron than the 2s electrons in beryllium

Question 12

Why does ionisation energy fall between nitrogen and oxygen

Answer 12

Marks the start of electron pairing in the p orbitals of the 2p sub shell
The paired electrons in the 2p orbitals of oxygen repel one another, making it easier to remove an electron

Question 13

What is metallic bonding?

Answer 13

Bonding for metals
Each atom donates its negative outer shell electrons to a shared pool of electors, which are delocalised. The positive ions left behind consist of the nucleus and the inner electron shells of the metal atoms

It is the strong electrostatic attraction between cations and delocalised electrons

Question 14

Function of cations and delocalised electrons in metallic bonding?

Answer 14

Cations are fixed in position
Delocalised electrons are mobile and can move around / carry charge

Question 15

In a metal structure, billions of metal atoms are held together by metallic bonding in a….

Answer 15

Giant metallic lattice

Question 16

Properties of metals

Answer 16

Strong metallic bonds
High electrical conductivity
High melting and boiling points

Question 17

Electrical conductivity in a metal?

Answer 17

They can carry charge in both solids and liquids
When a voltage is applied across a metal, the delocalised electrons can move through the structure and carry charge.

Question 18

Many billions of atoms held together by a network of strong covalent bonds to form…

Answer 18

Giant covalent lattice

Question 19

3D structure in structures with covalent bonds?

Answer 19

Tetrahedral (109.5)

Question 20

Properties of giant covalent lattices

Answer 20

MP/BP: high mp/bp because covalent bonds are strong.
Solubility: insoluble in almost all solvents
Electrical conductivity: non conductors except graphene and graphite