H2O, or water, is formed when two hydrogen atoms bond with one oxygen atom. This bonding occurs through the sharing of electrons.
The Chemical Reaction
The formation of water is a chemical reaction represented by the following equation:
2H₂ + O₂ → 2H₂O
This means two molecules of hydrogen gas (H₂) react with one molecule of oxygen gas (O₂) to produce two molecules of water (H₂O). This reaction releases energy in the form of heat and, sometimes, light, making it an exothermic reaction.
The Bonding Process
Here's a more detailed look at the bonding process:
-
Atomic Structure: Hydrogen (H) has one electron, and oxygen (O) has six electrons in its outermost shell.
-
Sharing Electrons (Covalent Bond): Oxygen needs two more electrons to fill its outer shell and become stable. Each hydrogen atom needs one more electron. To achieve stability, oxygen shares one electron with each of the two hydrogen atoms. This sharing creates a covalent bond.
-
Water Molecule Formation: The sharing of electrons results in a stable water molecule where the oxygen atom is covalently bonded to two hydrogen atoms. The molecule has the formula H₂O.
Polarity of Water
It is important to note that the sharing of electrons between oxygen and hydrogen is not perfectly equal. Oxygen is more electronegative than hydrogen, meaning it attracts electrons more strongly. This unequal sharing of electrons results in a partial negative charge (δ-) on the oxygen atom and partial positive charges (δ+) on the hydrogen atoms. This makes water a polar molecule, giving it unique properties that are essential for life.
