The primary reason sodium ions are smaller than sodium atoms is that the ion has only two shells of electrons (the atom has three). Some resources suggest the ion gets smaller since
Why does the K+ ion have a smaller radius than Na+? - Quora
Mini-video on ion size (video) | Khan Academy
Ionic radius - Wikipedia
7.3: Sizes of Atoms and Ions - Chemistry LibreTexts
3.3: Predicting Charges of Ions - Chemistry LibreTexts
From Lithium‐Ion to Sodium‐Ion Batteries: Advantages, Challenges, and Surprises - Nayak - 2018 - Angewandte Chemie International Edition - Wiley Online Library
How Comparable Are Sodium-Ion Batteries to Lithium-Ion Counterparts? | ACS Energy Letters
Why does the Na+ ion have a smaller radius than the Na atom? - Quora
Research Development on K-Ion Batteries | Chemical Reviews
Ionic and Atomic Radius - Periodic Trends - YouTube
Ions in Solution
File:Action potential ion sizes.svg - Wikimedia Commons
Which ion has the largest radius? "Na"^(+), "Ga"^(3+), "K"^(+), "Mg"^(2+), "Ca"^(2+) | Socratic
Electrode Materials for Sodium-Ion Batteries: Considerations on Crystal Structures and Sodium Storage Mechanisms | SpringerLink
High Stability and Long Cycle Life of Rechargeable Sodium-Ion Battery Using Manganese Oxide Cathode: A Combined Density Functional Theory (DFT) and Experimental Study | ACS Applied Materials & Interfaces
![Frontiers | Hydrated Sodium Ion Clusters [Na+(H2O)n (n = 1–6)]: An ab initio Study on Structures and Non-covalent Interaction](https://www.frontiersin.org/files/Articles/468925/fchem-07-00624-HTML/image_m/fchem-07-00624-g001.jpg "Frontiers | Hydrated Sodium Ion Clusters [Na+(H2O)n (n = 1–6)]: An ab initio Study on Structures and Non-covalent Interaction")
Frontiers | Hydrated Sodium Ion Clusters [Na+(H2O)n (n = 1–6)]: An ab initio Study on Structures and Non-covalent Interaction
The Role of a Sodium Ion Binding Site in the Allosteric Modulation of the A2A Adenosine G Protein-Coupled Receptor - ScienceDirect
Measurements of the size and correlations between ions using an electrolytic point contact | Nature Communications
Size does matter | Max Planck Institute for Multidisciplinary Sciences
Ionic Radius Trends, Basic Introduction, Periodic Table, Sizes of Isoelectric Ions, Chemistry - YouTube
Ions in Solution
Size of Atoms
Why the size of Sodium atom is greater then sodium ion?size of Flourine atom is smaller then its ion - YouTube
Media Portfolio
Towards K‐Ion and Na‐Ion Batteries as “Beyond Li‐Ion” - Kubota - 2018 - The Chemical Record - Wiley Online Library
