Bonding
Atoms of most elements do not exist alone in nature. They bond to other atoms to form molecules. A molecule is formed when two or more atoms join together chemically.
If they bond to another atom of the same element, they form a special kind of molecule also known as a pure compound.
All compounds are molecules but not all molecules are compounds.
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What is chemical bonding?
The atoms of most elements are reactive which means that they tend to join to the atoms of other reactive elements. The joining of atoms of elements is called chemical bonding. Chemical bonding produces compounds. A compound is a substance made of the atoms of 2 or more different elements, chemically bonded (joined).
Why do some atoms bond and others do not?
- Chemical bonding is determined by the number of valence electrons in the outermost energy level.
- An atom is chemically stable if its outermost energy level is completely filled with electrons. For the atoms of most elements, the outermost energy level is filled when it contains 8 electrons. If an atom has only one energy level, it is complete with 2 electrons.
· When the outermost energy level is complete, an atom won’t naturally combine with atoms of other elements to form compounds. It won’t form chemical bonds. We say these atoms are inert. They do not form chemical bonds under normal conditions because the atoms of these gases have outermost energy levels that are filled.
· If an atom does not have a complete outermost energy level, it tends to lose, gain, or share electrons with other atoms to have outermost levels that are complete. When gaining, losing, or sharing electrons, bonds of attraction form between the atoms, and compounds form from these bonds.
Bonding Practice (Use for Thursday's homework)
Law of Conservation of Mass