Ionic Bonding Homework Help
Common Examples of Ionic Bonds
Table Salt (NaCl)
Sodium is a silvery-white metal and clorine a yellowish-green non-metal. The most common and most popular example of ionic bonds is the combination of these two elements which produces sodium chloride, commonly known as the table salt. In this ionic bonding, an electron from the sodium atom is transferred to the chlorine atom which creates oppositely charged chloride and sodium atoms. With the electrostatic forces holding them together, they become sodium chloride. This is a fascinating example of chemical bonding since it shows that two potentially harmful elements like sodium and chlorine, when combined, can become something safe for human consumption.
Calcium Chloride (CaCl)
Calcium is a metal which is silvery gray in color. Chlorine, on the other hand, is a yellowish-green non-metal. The transfer of electrons between chlorine and calcium results in the formation of the ionic compound known as calcium chloride. CaCl has several uses in various industries. In construction it can be used in soil solidification. It enhances dye retention in paper manufacturing. It helps in highway maintenance in the control of ice or snow. And in medicine, it can be used in the treatment of patients with low levels of calcium in the blood.
Magnesium Oxide (MgO)
Magnesium is a silvery-white metal, and oxygen is a gas which is colorless. Magnesium oxide is the result of oxygen and magnesium combined. In medicine, it is incorporated as a food supplement. In other industries, it is used as a component in fiberglass, cements, steels and alloys.
Potassium Bromide (KBr)
Potassium is a metal, silvery-white in color. It easily decomposes when exposed to water, and it also catches fire easily during this reaction. Bromide, a non-metal, is a liquid with reddish-brown color. As one of the examples of ionic bonds, the chemical bonding that occurs between bromide and potassium produces potassium bromide. KBr has uses in veterinary medicine as a treatment for animals with epilepsy. It is also utilized in photographic plates and paper manufacturing.
In a covalent bond electrons are shared between two atoms. In an ionic bond electrons are transferred from one atom to another, forming a postive and a negative ion. The ions are held together by the electrostatic attraction between the opposiste charges.
An ionic bond forms between a metal and a non-metal, because metals lose electrons and non-metals gain electrons. Each metal atom tends to lose the number of electrons that leaves it with a complete octet, or eight electrons in its outer level. The group one elements such as lithium and sodium have one valence or outer electron so by losing this electron they have a complete octet in the next lower energy level. This makes them very reactive. The group 2 elements have two valence electrons, both of which they lose easily. The non-metals achieve a complete octet by gaining electrons. For example, the group 7A elements such as fluorine and chlorine have 7 valence electrons so they react easily to gain one.
Atoms that form covalent bonds also achieve a complete octet. For example, oxygen exists as the molecule O2 with a double covalent bond because each oxygen atom has six valence electrons. When two pairs of electrons are shared between them they have a complete octet. The shared electrons are considered valence electrons for both atoms.
Covalent bonds in which the electrons are shared unevenly are called polar covalent bonds. In water, oxygen forms polar covalent bonds to the two hydrogen atoms. The electrons are more attracted to oxygen than hydrogen because oxygen is more electronegative.