Three SP3 hybrid orbitals contain only one electron, while fourth hybrid orbital is empty. Thallium is more reactive & oxidizes in air.īonding & shapesDialuminium Hexabromide (Al2Br6) Al undergoes SP3 hybridization using one S & three P orbitals. Indium & Gallium are stable in air & not attack by water. Aluminum is stable in air because it forms stable oxide film, but in absence of film metal is rapidly oxidizes & decomposes water. Amorphous Boron is reactive it burns in air to form oxides B2O3, nitrides BN & halogens BX3. They shows tendency to form covalent compound. Trends in Properties 5) Reactivity: - These elements have slightly higher Ionization Potential than alkaline earth metals. Ga - * B & Al shows stable oxidation state +III, * Ga & In shows stable oxidation state +I & +III, * Tl shows stable oxidation state +I. decreases from B to Tl, stability of +I O.S. These elements forms trivalent covalent compounds e.g. This shows +III oxidation state, while Tl shows +I, which is most stable. Trends in Properties 4) Oxidation states: - General electron configuration of Gr. Thus the electro-negativity value does not fall as expected due to presence of extra d-electron & f-electron. The remaining two elements shows slight decrease i.e. However Ga (1.81) shows slight increase, which is unexpected. The electro negativity decreases from B (2.04) to Al (1.60), due to increase in size. Trends in Properties 3) Electro negativity: - It is the power of atom to attract electrons to itself. 6.0 eV because of introduction of d- orbital electrons. 8.3 eV, due to smallest size, Al has 5.98 eV due to increasing in size. value of depends on atomic size, nuclear charge & screening effect. Thus they held less tightly than s-electron. The p-electrons are away from nucleus compare to s-electron. IIIA elements have two s-orbital & one p-orbital electron. Trends in Properties 2) Ionization Potential: - The Gr. If trivalent ions are consider, the ionic radii of elements increases from B to Tl i.e. The atomic size increases from B to Al is 0.80 Å to 1.25 Å, but from Al to Tl size increase is very small i.e. Although nuclear charge increases, the addition of new shell is more effective & size increases steadily from B to Tl. from B to Tl, atomic & ionic size increases. Trends in Properties 1) Size of atoms & ions: As we go from top to bottom in Group i.e. So their electron configuration is ns2, np1. In these elements have three electrons in their outer orbital. Group IIIA – Boron Family Their position in periodic table is in Gr. beyond 4 due to absence of d-orbital while other elements can extends their coordination no. Boron hydroxides are acidic while hydroxides of other elements are amphoteric or basic. Boron halides are monomeric & covalent e.g. Oxides – B2O3 is Acidic Al2O3 & Ga2O3 are Amphoteric while In2O3 & Tl2O3 are basic. Boron is non-metal other elements of Gr.IIIA are metals. Boron differs due to its small size, high electro negativity & absence of d-orbital. The element Boron is differs in its behaviors from other member of Gr.IIIA, but it resembles the next period element i.e. Anomalous behavior of Boron – Boron is the first element of Gr. Their electron configuration is ns2, np1. Group IIIA – Boron Family The Gr.IIIA contains elements Boron (5B), Aluminium (13Al), Gallium (31Ga), Indium (49In), Thallium (81Tl). The groups of the p-block are: 13 (IIIB,IIIA): Boron Group 14 (IVB,IVA): Carbon Group 15 (VB,VA): Nitrogen Group 16 (VIB,VIA): Chalcogens 17 (VIIB,VIIA): Halogens 18 (Group 0): Noble gases (excluding Helium) The p-block contains all of the nonmetals (except for Hydrogen and Helium which are in the s-block) and semimetals, as well as some of the metals. In the elemental form of the p-block elements, the highest energy electron occupies a p-orbital. P-BLOCK The elements consists of the last six groups minus helium (which is located in the s-block). The Periodic Table of the Elements H He Elements that are polyatomic in their natural state Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Sb Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Du Sg Bo Ha Me Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Diatomic Octatomic ( 8 atoms per molecule) Tetratomic ( 4 atoms per molecule)Įlectron Affinity Ionization Potential Atomic Size Non Metallic Character Electron Affinity Metallic Character Ionization Potential Atomic Size Borawake Ganesh.Anilrao Department of Chemistry Jijamata College of Science and Arts, Bhende bk.