Why atoms form ions to achieve full outer electron shells

How sodium loses an electron to form a positive ion

Predicting common ions using periodic table groups

Finding electron counts in neutral atoms using the periodic table

Finding element identity and ion charge from proton and electron counts

Finding ion charges for sulfur and lithium from proton and electron counts

Finding protons and electrons in Cr3+ and F- ions

Finding protons and electrons for Sb³⁺ and Zn⁺ ions