pblokkiin

The p-block, or p-block region, of the periodic table comprises the elements whose outermost electrons occupy p orbitals. In most modern layouts, this block lies to the right of the s-block and includes the elements in groups 13 through 18, with helium not considered a p-block element. The defining feature is that the last electron enters a p orbital.

The p-block spans multiple periods, from period 2 to period 7 in standard tables. It contains a wide range of element types: metals such as aluminum, tin, and lead; metalloids such as boron, silicon, germanium, arsenic, antimony, and tellurium; nonmetals such as carbon, nitrogen, oxygen, and sulfur; and the halogens and noble gases (fluorine, chlorine, bromine, iodine, astatine, neon, argon, krypton, xenon, radon). This mix makes the p-block the most chemically diverse region of the table.

Properties within the block vary considerably. Bonding can be covalent or ionic, and compounds span a wide range of oxidation states. Electronegativity generally increases from left to right across the block, contributing to increasing nonmetallic character in the upper-right portion and metallic tendencies in the lower-left portion of the block. The noble gases are especially inert, while the halogens are highly reactive.

Applications and significance are broad. Carbon underpins organic chemistry and biochemistry; silicon dominates modern electronics and materials science; aluminum and other p-block metals have numerous structural and industrial uses; halogens form many essential reagents and compounds. The p-block elements collectively play a central role across chemistry, materials science, biology, and industry.