8. Which one of the following is true? Ionization potential
a. is the energy required to remove an electron from the innermost shell of an atom
b. is the ability of an atom to attract an electron pair
c. generally increases from left to right in a period in the periodic table
d. generally increases from top to bottom in a group in the periodic table
Ionization Potential MCQ: Correct Answer and Detailed Analysis
The correct option is c. generally increases from left to right in a period in the periodic table.
Option Breakdown
a. is the energy required to remove an electron from the innermost shell of an atom
This is incorrect. Ionization potential refers to the energy needed to remove the outermost (valence) electron from a gaseous atom, not specifically the innermost shell.
b. is the ability of an atom to attract an electron pair
This describes electronegativity, not ionization potential. Electronegativity measures shared electron attraction in bonds.
c. generally increases from left to right in a period in the periodic table
Correct. Across a period, nuclear charge rises while shielding stays constant, tightening hold on valence electrons and raising removal energy.
d. generally increases from top to bottom in a group in the periodic table
Incorrect. Down a group, valence electrons are farther from the nucleus with more shielding, so ionization potential decreases.
Ionization potential, or ionization energy, measures the energy to remove an atom’s valence electron. This key atomic property dictates reactivity and follows clear periodic table trends vital for chemistry exams.
Period Trend: Left to Right Increase
In a period, ionization potential rises due to higher atomic number boosting nuclear charge without added shielding. Valence electrons face stronger pull, demanding more energy for removal—e.g., Li to Ne shows steady climb.
Group Trend: Top to Bottom Decrease
Down a group, added electron shells increase distance and shielding from inner electrons, easing valence electron removal. Alkali metals exemplify this drop from Li to Cs.
Factors Influencing Ionization Potential
Atomic radius inversely correlates—smaller atoms hold electrons tighter. Exceptions occur at half-filled or full subshells for extra stability.
