Periodicity: Practice Questions

Which element in Period 3 has the highest first ionisation energy?

The melting points of four consecutive Period 3 elements are given in arbitrary order:
\(1414\text{ }^\text{o}\text{C}\), \(115\text{ }^\text{o}\text{C}\), \(44\text{ }^\text{o}\text{C}\), \(-101\text{ }^\text{o}\text{C}\).
Which element corresponds to the melting point of \(115\text{ }^\text{o}\text{C}\)?

Which graph correctly represents the general trend in atomic radius for the elements across Period 3 from sodium to chlorine?

Which element in Period 3 has the highest electrical conductivity at room temperature?

Which of the following describes the bonding, structure, and trend in atomic radius from magnesium to sulfur in Period 3?

State the name of the block in the Periodic Table to which sodium (\(Z = 11\)) and magnesium (\(Z = 12\)) belong.

Explain why the atomic radius decreases across Period 3 from sodium to chlorine.

Explain why the melting point of sulfur (\(\text{S}_8\)) is higher than that of chlorine (\(\text{Cl}_2\)), but lower than that of silicon, in terms of structure and bonding.

Across Period 3 from sodium to argon, the physical and atomic properties show distinct trends.

(a) State and explain the general trend in first ionisation energy across Period 3 from sodium to argon.
(b) Identify the Period 3 element that has the lowest melting point and explain why in terms of structure and bonding.

Consider the elements across Period 3 of the Periodic Table (from sodium to chlorine).

(a) State the trend in atomic radius across Period 3 from sodium to chlorine, and explain this trend in terms of atomic structure.

(b) Explain why the melting point of magnesium is higher than the melting point of sodium in terms of metallic bonding.

(c) State which element in Period 3 has the highest first ionisation energy.

(d) State the block in the Periodic Table to which silicon belongs and write its ground-state outer electron configuration.