Grouping Elements with Similar Chemical Properties Together

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Grouping elements with similar chemical properties together

Date: 4.10.2012

Objectives
The objective of this experiment is to experimentally investigate which elements show similar chemical properties.

Chemical principle
Calcium is a chemical element with symbol Ca and atomic number 20. Calcium is a dull gray, silver solid under standard conditions. Calcium atoms have an electron configuration of (2, 8, 8, 2) and 2 outermost shell electrons. Calcium is in group 2 and period 4 of the periodic table. Calcium commonly forms the cation Ca2+ by donating 2 electrons, reaching a stable electron configuration. Calcium is an alkaline earth metal. Magnesium is a chemical element with symbol Mg and atomic number 12. Magnesium is a shiny gray solid under standard conditions. Magnesium atoms have an electron configuration of (2, 8, 2) and 2 outermost shell electrons. Magnesium is in group 2 and period 3 of the periodic table. Magnesium commonly forms the cation Mg2+ by donating 2 electrons, reaching a stable electron configuration. Magnesium is an alkaline earth metal. Copper is a chemical element with symbol Cu and atomic number 29. Copper is red orange metallic luster under standard conditions. Copper atoms have an electron configuration of (2, 8, 18, 1) and 1 outermost electron. Copper commonly forms the cation Cu2+ by donating 2 electrons. Copper is in group 11 and period 4 of the periodic table. Copper is a transition metal. Calcium and magnesium have the same number of outer shell electrons and similar electron configurations. They are both in group 2 and have similar chemical properties. Copper has a very different number of outer shell electrons and electron configuration from magnesium and calcium. Copper is instead in group 11 and has very different chemical properties compared to magnesium and calcium. Hydrochloric acid is an acidic compound with the chemical formula HCl. A hydrochloric acid molecule consists of a hydrogen atom H and a chlorine atom Cl, bounded by a single covalent bond. Covalent bonds are a type of chemical bonding involving the sharing of pairs of electrons. Single covalent bonds are covalent bonds where one pair of electrons are shared, double covalent bonds are bonds where two pairs are shared, and this meaning extends to all other positive integers. Hydrochloric acid is very soluble in water and its solution in water is pale green. When magnesium is mixed with a hydrochloric acid solution, hydrogen chloride molecules ionize into ions H+ and Cl-. Magnesium ionizes into Mg2+ ions, transferring its electrons to hydrogen atoms. The hydrogen atoms then form single covalent bonds with each other, escaping as the diatomic, meaning with two atoms, gas H2. Magnesium and chlorine form the compound MgCl2. The compound is held together by a strong electrostatic force between the ions Mg2+ and Cl-. This type of chemical bonding involving the strong electrostatic attraction between ions is termed ionic bonding. This reaction can be summarized by the word equation: hydrochloric acid + magnesium → magnesium chloride + hydrogen Reactions like this, involving transfers of electrons or changes in oxidation states, are called redox reactions. Oxidation state refers to the hypothetical charge an atom would have if all bonds to atoms of different elements were completely ionic. Oxidation refers to an increase in oxidation state and oxidants refer to chemicals which cause other substances to become oxidized. Similarly, reduction refers to the decrease in an oxidation state and reductants refer to chemicals which cause other substances to become reduced. In this reaction, magnesium is initially neutral and the hydrogen ions from hydrochloric acid are initially positive. Then, magnesium transfers its electrons to the hydrogen ions. Thus, in this reaction magnesium is the reductant and hydrochloric acid is the oxidant. Calcium, since it has very similar chemical properties with magnesium, reacts with hydrochloric...
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