Ionic compounds are chemical compounds that are formed by an ionic bond, which means that two or more atoms combine by transferring or sharing one or more electrons. These compounds are also called electrovalent compounds. Ionic compounds include sodium chloride, sodium sulphide and sodium hydroxide.
In order to form an ionic bond, the elements must have opposite charges. In other words, one atom must have a negative charge while the second element has a positive charge. Because a negative charge attracts a positive charge, atoms with these properties are naturally drawn toward each other. Once joined, ionic compounds form crystals, which look like cubes under a microscope. Some crystals can be seen with the naked eye.
Ionic compounds have similar characteristics. Not only do they have high melting and boiling points, but these compounds are also hard and brittle. Ionic compounds also conduct electricity when they are dissolved in water. Common ionic compounds include ordinary table salt.
In most cases, ionic compounds are formed from a non-metal and a metal atom. This is because metal atoms have positive charges and non-metal atoms normally have negative charges. When an atom has a positive charge, it is called a cation. When it has a negative charge, it is called an anion.