In this lab, six different metals were tested for their reactivity in water. From less reactive to most reactive, the metals were as follows: Aluminum, Magnesium, Calcium, Lithium, Sodium, and Potassium

Discussion

In this lab, six different metals were tested for their reactivity in water. From less reactive to most reactive, the metals were as follows: Aluminum, Magnesium, Calcium, Lithium, Sodium, and Potassium. A pattern found in the periodic table explaining the reactivity of metals is the further down in a family, and the further left in a period, the more reactive the metal will be.

        Aluminum and Magnesium were both the less reactive. Neither of the metals produced hydrogen, or not enough to have a positive test to prove it was there.

                Metals  +  H O                H  + Metal Hydroxide

        Calcium gave off a large amount of Hydrogen gas. Lighting a splint, placing it in the test tube, and hearing a loud “pop” proved this. When the calcium was placed in the water, it caused the temperature to rise to such a high level it was not possible to hold with bare hands. This could be because the electrons are moving so quickly that it causes the temperature to rise. The calcium formed a white, powder-like precipitate at the bottom of the test tube.

        Lithium, Sodium, and Potassium all had very violent reactions in water. Phenolphthalein was added to the beakers after the metals had reacted, and the water turned a pink/ purple color proving that these metals make bases, and therefore have a pH between eight and.

        Common reactions between metals were they all formed hydrogen gas, even if it was a very small amount. Lithium, Sodium, and Potassium all tested positive to be a base with phenolphthalein, and all had an oily surface.

        A pattern found in the periodic table explaining the reactivity of metals is the further down in a family, and the further left in a period, the more reactive the metal will be. This is because the elements in period I, Lithium, Sodium, and Potassium, only have one valence electron, and it is quite simple to lose it. Also, the further down the family, the more the ionization energy decreases because of the shielding effect (the inner electrons block the attraction of the nucleus for outer electrons) and atomic radius (the greater the distance between the nucleus and the outer electron). However, the further to the right of the periodic table, the more the ionization energy increase because of the nuclear charge, electron arrangement ( an electron in a full of a half full energy level requires additional energy to be removed), and atomic radius. This explains why Aluminum was the least reactive, and Potassium was the most reactive.