Group 3A 1 3 The Boron Family

Boron (B) heads the third family of main-group elements, but its properties are not representative, as the Group 3A(13) Family Portrait shows. Metallic aluminum (Al) is more typical of the group, but its great abundance and importance contrast with the rareness of gallium (Ga), indium (In), and thallium (Tl). 

With respect to their physical properties, boron is a black, hard, very high-melting, network covalent metalloid, but the other 3 A members are shiny, relatively soft, low-melting metals. Aluminum s low density and three valence electrons make it an exceptional conductor for a given mass, it conducts a current twice as effectively as copper. Gallium has the largest liquid temperature range of any element it melts in your hand but does not boil until 2403°C. 

What New Features Appear in the Chemical Properties of Group 3A(13)  

Atomic mass Valence e configuration Common oxidation states 

A1 becomes covered with a layer of AI2O3 that prevents further reaction. 

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Group 3A(13) The Boron Family 432 How the Transition Elements Influence... 

Boron, Group 3A(13) B is the only member of its group to form a complex family of compounds with metals and covalent compounds with hydrogen (boranes). 

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