The atomic number of an element X is 13. What will be the number of electrons in its ion X3+?
10
If the atomic number of an element X is 13; the number of electrons in its ion X3+ will be 10. This is because X3+ is a positively charged cation. An atom loses electrons from its valence shell and becomes positively charged ion called cation. Here, Atom X loses 3 electrons and acquires 3+ charge. Therefore the number of electrons lost will be 3 and the number of electrons in its ion X3+ will be 10.