Question

Why is there a phenomenal decrease in ionization enthalpy from carbon to silicon?

Answer 1

There a huge decrease in ionization enthalpy from carbon to silicon because of increase in atomic size as we go down the group and also due to screening effect. The force of attraction between the nucleus and the valence electrons (effective nuclear charge) decreases in silicon as compared to carbon. Therfore there is a great decrease in ionization enthalpy from carbon to silicon.

Answer 2

Both Carbon(C) and Silicon(Si) belongs to 13th Group of Modern Periodic Table and are of p-block elements. As due to increase in atomic size and screening effect, effective nuclear charges decreases from C To Si. Thus, there is a phenomenal decrease in ionization energy of C to Si.

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