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The Relative Activity of Metals

  • Page ID
    3090
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    Chemical Concepts Demonstrated

    • Relative activity of metals
    • Metal classification based on reactivity

    Demonstration

    • Drop samples of sodium, magnesium, aluminum, and iron metal into water.
    • Drop samples of magnesium, aluminum, and iron metal into 6M HCl.
    METAL WATER HCl
    sodium Highly reactive in water. Highly reactive in acid.
    magnesium No reaction in water at room temperature. Reacts rapidly in acid.
    aluminum No reaction in water at room temperature. No reaction.
    iron No reaction in water. No reaction.

    Explanation

    Notice the metals' locations in the periodic table. The most reactive metals have the greatest tendency to lose electrons to form positively charged ions. Metals, therefore, become more reactive as they are located further to the left on the periodic table. Based on the activities of the metals, the four metals can be separated into three different categories:

    1. Reactive in both acid and water (i.e. high reactivity): sodium (and, by extension, other alkali metals)
    2. Reactive in acid, but not water (i.e. moderate reactivity): magnesium (and, by extension, other alkaline-earth metals)
    3. Unreactive in both acid and water (i.e. low reactivity): aluminum and iron (and, by extension, other transition and Group IIIA metals)

    The Relative Activity of Metals is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by George Bodner.

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