Ions and Isotopes

Based on the information on p34 IGCSE Chemistry Second Edition

Ion

    • A positively or negatively electrically charged particle
    • An atom or group of atoms which has lost (or gained) one or more electrons
    • When an atom loses one or more electrons, it becomes a positively charged ion
    • When an atom gains one or more electrons, it becomes a negatively charged ion
    • An ion may contain MORE THAN ONE TYPE OF ATOM
      • eg. NO3-
      • (a Nitrate Ion)
    • An ion may possess MORE THAN ONE UNIT OF CHARGE (either negative / positive)
      • eg. Al3+ , O2-, SO42-
      • repsectively an Aluminium ion, an Oxygen ion and a Sulphate ion

Isotopes

    • Atoms of the same element which have a different number of neutrons

There are two types of Isotopes:

    1. The ones that are stable
    2. The ones that are UNstable

1. The ONES THAT ARE STABLE

Generally, isotopes behave the same way in chemical reactions

Effect of the extra neutrons:

    • Alter the mass of the atom
    • Alter the properties which depend on the mass of the atom
        • eg. Density

2. The ONES THAT ARE UNSTABLE

    • The EXTRA NEUTRONS in their nuclei are radioactive
    • These isotopes are called radioisotopes
      • eg. Uranium (power source in nuclear reactors)

Atomic Structure and Periodic Table

links to other subtopics in this section can be found here.

Chemistry-IGCSE