Q.Across the p-block, describe the general trend in

[!TLDR] Down a p-block group: atomic size generally increases, ionisation enthalpy generally decreases, and metallic character increases; Group 13 shows an ionisation-enthalpy irregularity at gallium. [!ANSWER] Atomic size increases, ionisation enthalpy decreases, and metallic character increases on descend …

Three broad trends recur across every p-block group on descending from the lightest to the heaviest member. Atomic size generally increases down a group, as each successive element adds a further principal quantum shell, though the increase from the second-period to third-period member is often smaller than expected (as seen going from boron to aluminium, or carbon to silicon), because the intervening $d$/$f$ electrons of the heavier elements shield the nucleus poorly. Ionisation enthalpy generally decreases down a group, since the outermost electrons lie progressively farther from the nucleus and are more effectively shielded by the growing number of inner shells, making them easier to remove. Metallic character increases down a group: the lightest member of a p-block group is typically a nonmetal or metalloid (boron, carbon), while the heaviest members become distinctly metallic (thallium, lead), reflecting the progressively easier loss of valence electrons and increasingly delocalised, metallic bonding. A well-known irregularity in the ionisation-enthalpy trend occurs specifically in Group 13: gallium's first ionisation enthalpy is anomalously close to, rather than clearly lower than, aluminium's, beca …

State the three general p-block trends (size increases, ionisation enthalpy decreases, metallic character increases down a group), then cite the specific …

Stating that ionisation enthalpy decreases smoothly with no exceptions; forgetting metallic character trend direction (some students r …