Atomic radii (van der Waal's radius)

Periodic trend in van der Waal's radius

1. Atomic Radius ( van der Waal’s radius) Dr. Mithil Fal Desai Shree Mallikarjun and Shri Chetan Manju Desai College Canacona Goa

2. Atomic radius r Radius = distance of valance electron of outermost orbit to the centre of the atom How do we measure? e -

3. Vander Waal’s force Distance Energy 2r

4. van der Waal’s radius 2r v an der Waal’s radius of element is half the inter-nuclear distance when the valance shells of the two atoms are in not bonded together. r r

5. Periodic trend H 120-145 He 180 Li 180 Be B C 165-170 N 155 O 150 F 150-160 Ne 160 Na 130 Mg Al Si P S Cl Ar 190 K 280 Ca Sc Ti V Cr Mn Fe Co Ni 160 Cu 140 Zn 140 Ga 190 Ge As Se 190 Br 180-200 Kr 200 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd 160 Ag 170 Cd 160 In 190 Sn 220 Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt 170-180 Au 170 Hg 150 Tl 200 Pb 200 Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Rg 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 v an der Waal radii in pm Increases Decreases