3.1.1- Periodicity

Question 1

How is the periodic table arranged?

Answer 1

Based on increasing proton number

Question 2

What do the periods show?

Answer 2

Repeating trends in physical and chemical properties

Question 3

What do groups show?

Answer 3

Elements with similar chemical properties

Question 4

What happens to atomic radius along a period?

Answer 4

Decreases due to increased nuclear charge

Question 5

What happens to atomic radius down a group?

Answer 5

Increases as increased shielding which reduces nuclear attraction

Question 6

What is first ionisation energy?

Answer 6

The minimum energy required to remove one mole of electrons from one mole of atoms in a gaseous state

Question 7

What happens to ionisation energy as you go along a period?

Answer 7

Increases due to decreasing atomic radius and greater electrostatic forces of attraction

Question 8

What happens to ionisation energy as you go down a group?

Answer 8

Decreases due to increasing atomic radius and electron shielding which reduces electrostatic forces of attraction

Question 9

What about ionisation energies indicates what group an element is in?

Answer 9

A large jump between ionisation energies

Question 10

What are the exceptions to an increasing trend of ionisation energy in period 2?

Answer 10

Boron and oxygen

Question 11

Why is boron an exception?

Answer 11

It has a lower ionisation energy due to the energy difference between the 2s and 2p sub-shells as the electron is being removed from a higher energy level that is further from the nucleus

Question 12

Why is oxygen an exception?

Answer 12

Due to repulsion within the 2p orbital when two electrons with opposite spins are placed in the same orbital, so electrons can be removed more easily

Question 13

What are the exceptions of ionisation energies increasing in period 3?

Answer 13

Aluminium and sulfur

Question 14

What is a metallic bond?

Answer 14

Strong electrostatic attraction between cations and delocalised electrons

Question 15

What are the properties of metallic properties?

Answer 15

-good conductors
-malleable as layers of ions can slide over each other
-high mp

Question 16

What is diamond?

Answer 16

A macro molecular structure made up of carbon atoms, each of which are bonded to 4 further carbon atoms, providing a rigid structure

Question 17

What is graphite?

Answer 17

A macro molecular structure where each carbon is bonded to three other carbon atoms in flat sheets, so there is one delocalised electron per carbon atom so can conduct electricity

Question 18

Why is graphite a good lubricant?

Answer 18

Has weak London forces between layers, which allows layers to slide over each other

Question 19

What is graphene?

Answer 19

Consists of 2D sheets of graphite that are one atom thick. The sheets are formed of hexagonal carbon rings that create a very strong, rigid material that is lightweight and conducts electricity

Question 20

What is the trend of melting points along period 2?

Answer 20

Increases up to carbon, then is very low again

Question 21

What is the trend of melting points along period 3?

Answer 21

Increases, then shoots up for silicon as it’s macro molecular, then decreases again, slightly peaking at sulphur, then decreasing again