# What is the formula for dihydrogen monoxide?

Feb 18, 2017

${H}_{2} O$

#### Explanation:

The first part of the name, "dihydrogen," implies the presence of two hydrogen atoms. The second part, "monoxide," implies the presence of one oxygen atom. Therefore, you have two hydrogen atoms and one oxygen atom to make up each molecule. Sound familiar?

The common name is water, and it has the chemical formula ${H}_{2} O$.

Basic guidelines on naming other covalent inorganic molecules:

• Greek prefixes are used to indicate how many of each element are in a compound (e.g. mono, di, tri, tetra, etc.).
• The more electronegative element is written last and its ending is changed to –ide.
• The prefix mono is never used for naming the first element of a compound.
• The final "o" or "a" of a prefix is often dropped when the element begins with a vowel.