Chemical Bonding

There are a total of 3 types of bonding, ionic bonding, covalent bonding and metallic bond (which we would be learning in Secondary 3).

An ionic bond is formed when a atom accepts or gives one or more of its valence electrons to one or more atoms. This way, all atoms must also have the atomic structure of a noble gas in order to form an ionic bond. One of the types of atoms must also be a metal while the other is non-metal. When an atom loses or gains electrons, it is no longer electrically neutral and is now called a ion. A negative ion is called a anion while a positive ion is called a cation.

An example of a ionic bond is between sodium and chlorine. With sodium being the metal and chlorine being the non-metal, sodium gives one of its valence electrons to chlorine and both of the atoms have a atomic structure of a noble gas. Both

Covalent bonding is formed when two or more atoms share their valence electrons with one another. Both atoms must be non-metal for covalent bonding to take place. After the bonding, all the atoms in the bond must have the atomic structure of a noble gas. When two atoms share their electrons and they only share one valence electron, both of the atoms form a single covalent bond. For example, two hydrogen atoms share one electrons with each other. Both electrons form a single covalent bond and both atoms also have the atomic structure of the element helium. When two atoms share two electrons, both atoms form a double covalent bond. Two atoms can also form triple covalent bonds when they share three electrons.

Extra: Metallic bonding is formed when a lot of metal atoms give up their valence electrons and become cations. These electrons move around between the metal ions and occupy the spaces between the ions. These electrons are called mobile electrons. Each of the positive ions are attracted to these electrons and it is this attractive force that holds the ion and electrons in the metal together.