Practice: Give the correct number of protons, neutrons and electrons for the following isotope: 
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Ions represent elements that possess either a positive charge or a negative charge.
Ions and Stable Electron Arrangements
Concept #1: Ions
A positively charged ion is called a cation and a negatively charged ion is called an anion.
Concept #2: Ion Formation
Ions are formed from either the loss or gain of electrons by a neutral element.
Example #1: Determine the number of protons, neutrons, and electrons for the following cation 2713Al+3.
Practice: In which pair are the two species both isoelectronic and isotopic?
Practice: One isotope of a metallic element has a mass number of 65 and 35 neutrons in the nucleus. The cation that this atom forms has 28 electrons. What is the symbol of the cation?
Practice: Which of the following is the symbol for the ion with a +4 charge, 30 neutrons and 21 electrons?
Practice: Fill in the gaps for the following table.
