Arrange the following elements in order of decreasing first ionization energy: S, Ca, F, Rb, and Si.
Part B Arrange the following elements in order of decreasing first ionization energy: S, Ca, F, Rb, and Si. Rank from largest to smallest. To rank items as equivalent, overlap them. Largest first ionization energy Smallest first ionization energy The correct ranking cannot be determined
The Correct Answer and Explanation is :
The correct ranking for the elements in order of decreasing first ionization energy is:
F > S > Si > Ca > Rb
Explanation:
1. First Ionization Energy Defined:
The first ionization energy is the energy required to remove the outermost electron from a neutral atom in the gas phase. It depends on the following factors:
- Nuclear charge (Z): A higher nuclear charge attracts electrons more strongly, increasing ionization energy.
- Atomic radius: Smaller atoms have higher ionization energy because their electrons are closer to the nucleus and more strongly attracted.
- Shielding effect: Inner electrons reduce the effective nuclear charge experienced by outer electrons, lowering ionization energy.
2. Analyzing Each Element:
- Fluorine (F):
Fluorine is in Group 17 (halogens) and has the smallest atomic radius among the given elements. It has a high effective nuclear charge and minimal shielding, giving it the highest ionization energy. - Sulfur (S):
Sulfur is in Group 16, below oxygen, and has a larger atomic radius than fluorine. While its nuclear charge is greater than fluorine, the additional shielding and distance from the nucleus lower its ionization energy compared to fluorine. - Silicon (Si):
Silicon is in Group 14. It has a larger atomic radius and lower nuclear charge than sulfur, so its ionization energy is lower than sulfur’s. - Calcium (Ca):
Calcium is an alkaline earth metal in Group 2. Metals have lower ionization energies than nonmetals because of their larger atomic radii and less effective nuclear charge. Its ionization energy is lower than that of Si. - Rubidium (Rb):
Rubidium is in Group 1 (alkali metals) and has the largest atomic radius among the given elements. Its valence electron is far from the nucleus and experiences significant shielding, giving it the lowest ionization energy.
Conclusion:
The ranking reflects the periodic trends in ionization energy: increases across a period (left to right) and decreases down a group (top to bottom).