3.3. Chemical Formula http://www.ck12.org
- Q:A molecule of the covalent compound nitrogen dioxide consists of one nitrogen atom (N) and two oxygen
atoms (O). What is the chemical formula for this compound? - A:The chemical formula is NO 2.
Summary
- Compounds are represented by chemical formulas. Elements in a compound are represented by chemical
symbols, and the ratio of different elements is represented by subscripts. - There are different rules for writing the chemical formulas for ionic and covalent compounds.
Vocabulary
- chemical formula: Symbol of a chemical compound using element symbols and subscripts to represent the
ratio of atoms in the compound.
Explore More
At the following URL, do the online learning activity on chemical formulas. Then take the quiz at the end of the
activity to check your comprehension.
http://www.wisc-online.com/Objects/ViewObject.aspx?ID=GCH603
Review
- Complete the following analogy: A chemical symbol is to an element as a chemical formula is to a(n) -
. - The compound sodium sulfide consists of a ratio of one sodium ion (Na+) to two sulfide ions (S^2 −). Write the
chemical formula for this compound. - A molecule of sulfur dioxide consists of one sulfur atom (S) and two oxygen atoms (O). What is the chemical
formula for this compound? - Identify the ratio of atoms in the compound represented by the following chemical formula: N^2 O^5.