Essential Elements

20 21 thE Pblock metals, metalloids and nonmetals Elements five to ten are the first members of the pblock. Up to six electrons inhabit three new doubleteardrop shaped porbitals arranged at right angles around the nucleus see page 38. They appear as solids carbon and aluminium, liquids bromine, and gases nitrogen and chlorine, depending on the balance of their interatomic and intermolecular forces. The lefthand side of the pblock mostly shines with solid metals. Ductile, malleable and conductive because of their footloose outer electrons, metals can be stretched into wires, squished into sheets or mixed together into alloys. Crossing the block from left to right, metals transform into non metals. These are dull brittle solids, liquids or gases that are poor conductors of heat and electricity. With full or nearly full orbitals they prefer to share electrons covalently. In this small corner we find many of the major players in the game of life, such as carbon, oxygen and nitrogen opposite top. In between lie the metalloids, a diagonal streak of ambiguous elements with aspects of both types of behaviour. Among these are the semiconductors boron, silicon, germanium and arsenic, which form the hearts of our computers and electronic gizmos. p block