What is a positively charged ion?
Positively charged ions are particles which have a greater number of protons than electrons.
Quick reminder - electrons have a negative charge, protons have a positive charge
A monoatomic ion with a positive charge forms when a single atom (monoatomic) loses 1 or more electrons while keeping all of its protons. This give the ion a net positive charge.
This video discusses the formation of both positive and negative monoatomic ions.
Polyatomic ions are groups of atoms with an overall positive charge because they have a larger number of protons than electrons.
This video discusses the make-up of polyatomic ions, including ammonium which has a positive charge.
Hope this helps!