IC1

Question 1

Does the first ionisation energy increase or decrease across the period and why?

Answer 1

Increases

Increasing attraction between the outer shell electrons and the nucleus, due to the number of protons increasing

Question 2

Describe the melting point trend across period 3

Answer 2

Increases from Na to Al as the metal bonds get stronger due to an increased positive charge and increased number of delocalised electrons

Increases from Al to Is strongly due to the macromolecular structure of Is, so stronger covalent bonds which need a lot of energy to break

Decreases from Si to Ar due to the weaker van Der Waals forces between molecules (S8>P4>Cl2)

Question 3

Does the atomic radius increase or decrease across the period and why?

Answer 3

Decreases

Proton number increases so stronger nuclear charge so electrons are pulled closer to the nucleus. Also no extra shielding effect