Chemical+Bonding+Between+Atoms

There are two types of chemical bonds that join atoms together: 1. Ionic Bonds 2. Covalent bonds

__Ionic Bonds__

This is an attraction between oppositely charged ions. Atoms want to have their outermost electron shell full of electrons, so for example if Sodium has only one electron in its outermost shell, and Chlorine has seven (the limit to that particular shell is eight) Sodium would give the lone electron in it's outer shell to Chlorine, so that it can have it's outermost shell full. Chlorine also ends up having its outermost shell full with the gained electron, so both atoms' outer shells are full. Because Sodium lost an electron it becomes positively charged, and since Chlorine gained an electron it becomes negatively charged. Since oppositely charged atoms (ions) are attracted to each other, Sodium and Chlorine are bonded together, forming NaCl (salt).

An Ionic Bond between Sodium and Chlorine IonicBond.gif

__Covalent Bonds__ There are two types of covalent bonds:
 * Polar- A polar covalent bond occurs when electrons are not shared equally between atoms.
 * Non-polar- A non-polar covalent occurs when electrons are shared equally between atoms.

This type of bond occurs when atoms share electrons. If a Carbon atom has six electrons in it's outer shell (and the capacity is eight), two Carbon atoms come together and share two electons, so each atoms outer shell becomes full. In this example the electrons are shared equally between the two atoms, because they have an equal electronegative force. This type of covalent bond is called a Non-Polar Covalent Bond. In another example, two Hydrogen atoms form covalent bonds with an Oxygen atom. Since the Oxygen atom has a greater electronegative force than the two hydrogen atoms, the shared electrons are drawn closer to the Oxygen atom, making the Oxygen atom slightly negative and the Hydrogen atoms slightly positive. This unequal sharing of electrons in a covalent bond is called a Polar-Covalent Bond.

A Polar-Covalent Bond between an Oxygen and two Hydrogen atoms covalent-water.JPG