AP EAPCET 07-Jul-2022 Shift 2 Paper

The Si, Ge and Sn belong to third, fourth and fifth period of group 14 of periodic table. Moving down the group, size of atoms increases, so the bond length order is
Si−Si<Ge−Ge<Sn−Sn
Bond enthalpy is inversely proportional to bond length, so bond enthalpy order is
Si−Si<Ge−Ge<Sn−Sn
297>260>240‌‌(kJ‌mol−1)