Answer: The given elements are arranged in order of increasing ionization energy as Pb < Sn < Ge < Si < C.
Step-by-step explanation:
The amount of energy required to remove a loosely bound electron from an isolated neutral gaseous atom is called ionization energy.
Larger is the size of an atom more easily it will lose its valence electrons. Hence, less will its ionization energy.
Whereas smaller is the size of an atom more energy will be required to pull out the electron. Hence, more will be its ionization energy.
This means that on moving down a group ionization energy decreases and on moving along a period from left to right the ionization energy decreases.
The given elements are C, Ge, Pb, Si, and Sn. All these elements belong to group 14 of the periodic table.
Therefore, these elements are arranged in order of increasing ionization energy as follows.
Pb < Sn < Ge < Si < C
Thus, we can conclude that given elements are arranged in order of increasing ionization energy as Pb < Sn < Ge < Si < C.