Periodicity

Question 1

How does Atomic Radius change across period 3?

Answer 1

Decreases as nuclear charge increases so electrons a more attracted to nucleus

Question 2

How does melting point change between Na and Mg in period 3?

Answer 2

increases between sodium and magnesium because increase in nuclear charge as they are both metallic structures

Question 3

How does melting point change between Mg and Al in period 3?

Answer 3

Stays mostly the same between magnesium and aluminium as Mg has a larger radius but lower nuclear charge and Al has a smaller radius but higher nuclear charge

Question 4

How does melting point change between Al and Si in period 3?

Answer 4

Increases significantly between aluminium and silicon as Al is metallic and Si is macromolecular with a tetrahedral structure with strong covalent bonds

Question 5

How does melting point change between Si and P in period 3?

Answer 5

Decreases significantly between silicon and phosphorus as phosphorus is a simple covalent structure with weak van der waals intermolecular forces

Question 6

How does melting point change between P and S in period 3?

Answer 6

Slight increase between phosphorus and sulfur as there are more atoms in a molecule (P4 and S8) so stronger van der waals

Question 7

How does melting point change between S and Cl in period 3?

Answer 7

decreases between sulfur and chorine as chlorine is CL2 and sulfur is S8 (vdw)

Question 8

How does melting point change between Cl and Ar in period 3?

Answer 8

Decreases between Chlorine and Argon as Cl2 and Ar so weaker vdw

Question 9

What is the trend in first ionisation energy across period 3?

Answer 9

Generally Increasing
Dips at:
Al- outer electron in 3p rather that 3s, so outer electron further from nucleus
S- has an electron pair in 3p which repel