Q.Write a short note on anamolous properties of the first element of p-block.

Step 1. Three factors together explain why the first member of every p-block group differs from the rest of its family: its exceptionally small size, its high ionisation enthalpy and high electronegativity, and the complete absence of d orbitals in its valence shell.

Step 2. Boron (group 13). Boron is a metalloid while the rest of group 13 are reactive metals; it shows a diagonal relationship with silicon (group 14) -- both elements' oxides are acidic, both form readily hydrolysed covalent hydrides, and (except for boron trifluoride) both elements' halides hydrolyse readily.

Step 3. Carbon (group 14). Carbon is strictly a non-metal, unlike the metalloid/metal members below it; uniquely it forms multiple bonds (C=C, C=O) and shows an exceptional tendency to catenation, which then collapses sharply down the group (C >> Si > Ge ≈ Sn > Pb).

Step 4. Nitrogen (group 15) and oxygen (group 16). Nitrogen, like carbon, forms multiple bonds (N=N, C=N, N=O) and, unusually for its group, exists as a diatomic gas; oxygen likewise exists as a diatomic gas unlike the rest of its family, and its high electronegativity lets it hydrogen-bond.

Step 5. Fluorine (group 17). The most electronegative element overall, fluorine also hydrogen-bonds; it shows only the -1 oxidation state (the heavier halogens can reach +1, +3, +5, +7 too); and it is both the strongest oxidising agent and the most reactive halogen.

State the three general causal factors first, then illustrate each with the specific anomaly shown by boron, carbon, nitrogen/oxygen and fluorine in turn.

• Listing only ONE group's anomaly (e.g. just boron) when the question asks generally about 'the first element of p-block' -- a complete answer should name the underlying factors AND illustrate them across several groups.