The element having greatest difference between its first and second ionization energies, is :

For any given series of spectral lines of atomic hydrogen, let $$\Delta \mathop v\limits^\_ = $$ $$\Delta {\overline v _{\max }} - \Delta {\overline v _{\min }}$$ be the difference in maximum and minimum frequencies in cm^–1. The ratio Lyman Balmer $${{\Delta {{\overline v }_{Lyman}}} \over {\Delta {{\overline v }_{Balmer}}}}$$ is :

The major product of the following reaction is :

Match the catalysts (Column I) with products (Column II).

Column I	Column II
(A) V2O5	(i) Polyethylene
(B) TiCl4/Al(Me)3	(ii) ethanal
(C) PdCl2	(iii) H2SO4
(D) Iron Oxide	(iv) NH3