Elements in which the last electron enters in the any one of the three p- orbital of their outermost shells – p-block elements
•
Gen. electronic configuration of outer shell is ns 2 np 1-6
The inner core of e-config. may differ which greatly influences their physical & to some extent chemical properties.
• The block of elements in the periodic table consisting of the main groups:
• Group 13( B to Tl)
• Group14( C to Pb)
• Group15( N to Bi)
• Group 16( O to Po)
• Group17( F to At)
• Group18( He to Rn)
( 1) Members at the top and on the right of the p-block are nonmetals( C, N, P, O, F, S, Cl, Br, I, At).
( 2) Those on the left and at the bottom are metals( Al, Ga, In, Tl, Sn, Pb, Sb Bi, Po).
( 3) Between the two, from the top left to bottom right, lie an ill-defined group of metalloid elements( B, Si, Ge, As, Te)
GROUP 13: The boron group
Outer Electronic Configuration:-ns 2 np 1
• group members: boron( B), aluminum( Al), gallium( Ga), indium( In)& thallium( Tl). All, except boron, are metals.
• Boron show diagonal relationship with Silicon; both are semiconductors metalloids & forms covalent compounds.
• Boron compounds are electron deficient, they are lack of an octet of electrons about the B atom.