Medium
Explain why cations are smaller and anions larger in radii than their parent atoms.
(N/A) Radius of positive ion $(cation)$: An atom loses electrons to form a positive ion. The size of the positive ion is smaller than its parent atom.
This is because the positive ion has fewer electrons than the parent atom, while the nuclear charge remains the same. Consequently, the remaining electrons experience a greater effective nuclear charge, pulling them closer to the nucleus.
Example: The radius of a sodium atom is $186 \ pm$, whereas the radius of a $Na^{+}$ ion is $95 \ pm$.
Radius of negative ion $(anion)$: When an atom gains an electron, it becomes a negative ion. The size of the negative ion is larger than its parent atom.
This is because when one or more electrons are added to the parent atom, the inter-electronic repulsion increases, and the effective nuclear charge per electron decreases, causing the electron cloud to expand.
Example: The radius of a fluorine atom is $95 \ pm$, whereas the radius of a fluoride ion $(F^{-})$ is $136 \ pm$.
This is because the positive ion has fewer electrons than the parent atom, while the nuclear charge remains the same. Consequently, the remaining electrons experience a greater effective nuclear charge, pulling them closer to the nucleus.
Example: The radius of a sodium atom is $186 \ pm$, whereas the radius of a $Na^{+}$ ion is $95 \ pm$.
Radius of negative ion $(anion)$: When an atom gains an electron, it becomes a negative ion. The size of the negative ion is larger than its parent atom.
This is because when one or more electrons are added to the parent atom, the inter-electronic repulsion increases, and the effective nuclear charge per electron decreases, causing the electron cloud to expand.
Example: The radius of a fluorine atom is $95 \ pm$, whereas the radius of a fluoride ion $(F^{-})$ is $136 \ pm$.
Explore More
Similar Questions
The ionic radius of $Na^{+}$ ions is $1.02 \ \mathring{A}$. The ionic radii (in $\mathring{A}$) of $Mg^{2+}$ and $Al^{3+}$,respectively,are
Which of the following has the largest ionic radius?
Easy
View SolutionGiven below are two statements $ : $
Statement $(I) :$ The metallic radius of $Al$ is less than that of $Ga$.
Statement $(II) :$ The ionic radius of $Al^{3+}$ is less than that of $Ga^{3+}$.
In the light of the above statements, choose the most appropriate answer from the options given below $ : $
Statement $(I) :$ The metallic radius of $Al$ is less than that of $Ga$.
Statement $(II) :$ The ionic radius of $Al^{3+}$ is less than that of $Ga^{3+}$.
In the light of the above statements, choose the most appropriate answer from the options given below $ : $
Which ion has the largest radius from the following ions?
Medium
View SolutionWhich of the following orders of atomic radius is correct?
Easy
View SolutionVedclass Products
For Students
Vedclass Test Series
Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.
Start Free TrialFor Teachers
Exam Paper Generator
Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.
Try FreeFor Institutes
Online Exam Module
Live online exams with unlimited students, 360° analytics & white-label branding.
See Demo