Periodicity 3.2.1.2

Question 1

What trends are observed in atomic radius from Na to Ar?

Answer 1

Atomic radius decreases from Na to Ar

This trend is due to the increasing nuclear charge which pulls the electrons closer to the nucleus.

Question 2

What is the trend in first ionisation energy from Na to Ar?

Answer 2

First ionisation energy increases from Na to Ar

This increase is attributed to the greater nuclear charge and the reduced atomic radius, making it harder to remove an electron.

Question 3

What is the relationship between melting point and atomic structure in Na–Ar?

Answer 3

Melting point varies based on structure and bonding

Metallic bonding in Na leads to lower melting points, while the covalent bonding in Ar leads to higher melting points.

Question 4

Explain why atomic radius decreases across a period.

Answer 4

Increased nuclear charge without additional shielding

The effective nuclear charge increases, pulling electrons closer and reducing the atomic size.

Question 5

Fill in the blank: The first ionisation energy is the energy required to remove an electron from a _______.

Answer 5

[atom]

Question 6

True or False: Melting point increases across the period from Na to Ar.

Answer 6

False

While melting points vary, they generally do not consistently increase across the period.

Question 7

What type of bonding is present in Na?

Answer 7

Metallic bonding

This type of bonding is characterized by a sea of delocalized electrons.

Question 8

What type of bonding is present in Ar?

Answer 8

Covalent bonding

Ar exists as monoatomic and does not bond with other atoms under normal conditions.

Question 9

Fill in the blank: The trend in atomic radius can be explained by the _______ of the elements.

Answer 9

[structure and bonding]

Question 10

Explain why first ionisation energy increases as you move from Na to Ar.

Answer 10

Greater nuclear charge and smaller atomic radius

This makes it more difficult to remove an electron due to increased attraction.

Question 11

What is the effect of shielding on atomic radius?

Answer 11

Shielding reduces the effective nuclear charge perceived by outer electrons

This allows outer electrons to be held less tightly, affecting atomic size.