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Ion formation

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Intros
Lessons
  1. Introduction to ions
  2. Recall particles and charge.
  3. Why atoms form ions.
  4. How atoms form ions.
  5. Predicting common ions.
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Examples
Lessons
  1. Use information in the Periodic Table to find the number of sub-atomic particles in elements.
    How many electrons are in an atom of the following species?
    i) P
    ii) Ru
    iii) Rb
    1. Identify atoms and their charge when given the number of sub-atomic particles.
      Identify the element and the charge on the particle described below.
      1. i) A particle with 50 protons and 52 electrons.
        ii) A particle with 13 protons and 10 electrons.
      2. i) A particle with 16 protons and 18 electrons.
        ii) A particle with 3 protons and 2 electrons.
    2. Find out the number of sub-atomic particles when given ions and their charge.
      Find the number of protons and electrons in the following species:
      1. i) Cr3+^{3+}
        ii) F−^-
      2. i) Sb3+^{3+}
        ii) Zn+^+
    Topic Notes
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    In this lesson, we will learn:
    • To understand the reason chemical atoms form ions and the particle that causes ionization.
    • To calculate the charge of ions from electron and proton numbers
    • To apply knowledge of ion charges to find number of electrons in ions
    • To predict an element's stable ions based on the Periodic table

    Notes:

    • Atoms are comprised of protons, neutrons and electrons. In a neutral atom, the number of electrons is equal to the number of protons.

    • Many elements and substances engage in chemical reactions to obtain a full outer shell of electrons, which involves metal atoms losing electrons to empty their outer shell ('dropping down a shell' in the process) and non-metal atoms gaining electrons to complete a full outer shell.

    • These changes in number of electrons changes the overall charge of an atom, if the number of protons and electrons isn't equal in an atom then it becomes a charged atom.

    • CHARGED ATOMS ARE CALLED IONS.

    • Chemical reactions only involve outer-shell electrons. They virtually never change the nucleus of an atom.

    • To find the charge of an atom or ion, subtract the number of electrons from the number of protons in the particle.

    • The electron shell configuration (and therefore its position in the Periodic Table) of an element is strongly related to the stable ions it is able to form – atoms gain or lose a number of electrons to fill their outer shell, which dictates their charge!

    • Ion formation normally occurs when electrons are transferred from one atom, usually a metal, and donated to another atom, usually a non-metal – this is how ionic compounds are formed.