Chapter 7 - Periodicity

Question 1

What is ionisation energy?

Answer 1

Ionisation energy measures how easily an atom loses electrons to form positive ions

Question 2

What is the first ionisation energy?

Answer 2

The 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

What factors affect ionisation energy?

Answer 3

-Atomic radius - the greater the distance the less the nuclear attraction so decreases the ionisation energy with a larger atomic radius
-Nuclear charge - The more protons in the nucleus of the atom, the greater the attraction between nucleus and electrons, so higher activation energy
-Electron Shielding - Electrons are -ve charged so inner shell electrons repel outer shell electrons (shielding effect) this reduces the attraction between the nucleus and the outer shell electrons.

Question 4

What is metallic bonding?

Answer 4

The strong electrostatic attraction between cations and delocalised electrons

Question 5

What structure do metals have?

Answer 5

Giant metallic lattice

Question 6

What physical properties do most metals have?

Answer 6

-Electrical conductors - can conduct when both solid and liquid, the delocalised electrons can move through the structure and carry charge
-High melting and boiling points - high temperature is required to provide enough energy to overcome the strong electrostatic attraction between cations and electrons
-Not soluble

Question 7

What are the properties of substances with a giant covalent lattice structure?

Answer 7

-High melting and boiling points - they are held together by strong covalent bonds which require high temperatures to overcome
-Insoluble
-Do not conduct electricity - (except graphite / graphene) they have no available electrons that can move to carry current