Core Concepts
In this tutorial, you will be introduced to the different types of chemistry prefixes. You will also learn the basics of these chemistry prefixes and how they are applicable in the real world today! Lastly, you will be given different examples to practice with naming chem prefixes.
Topics Covered In Other Articles
Introduction to Chemistry Prefixes
Number of Atoms: Prefixes
1: mono
2: di
3: tri
4: tetra
5: penta
6: hexa
7: hepta
8: octa
9: nona
10: deca
The above list shows the 10 most basic chemistry prefixes for naming compounds, which come from Greek. These prefixes can be used to name just about any compound. With a little bit of practice, naming compounds will become easier and easier! Don’t get frustrated with yourself if you don’t understand it right away.
Vocabulary of Chemistry Prefixes
Atom– the smallest unit of a chemical element, made from protons, neutrons, and electrons
Prefixes– the name that comes before the molecule
Compounds– a chemical species composed of two or more elements
Periodic table– a table of chemical elements that is arranged in order of atomic number
Oxidation State– a number assigned to an element that represents the number of electrons lost or gained
Transition Metal– elements from the d-block of the periodic table, which can have more than one configuration of valence electrons
Roman Numerals– tells you the oxidation state of the transition metal ion
Element– a substance that cannot be chemically broken down into simpler components
Molecular Compounds
A molecular compound consists of molecules whose formula represent the actual number of atoms bonded together in that molecule. Some examples of molecular compounds are water (H2O) and carbon dioxide (CO2). These compounds are held together by covalent bonds between atoms in the molecule.
Ionic Compounds
An ionic compound is a chemical compound held together by ionic bonding. These compounds are neutral overall. However, these compounds have many positively and negatively charged particles. Some examples of ionic compounds are sodium chloride (NaCl) and sodium hydroxide (NaOH).
Explanation of Naming Compounds
The naming system is used by determining the number of each atom in the compound. For example, a compound that has 5 atoms of a particular element would have the “penta” prefix before that element in the compound’s name. Once you have determined each prefix, you need to add the “ide” suffix if the second name in the compound is an element (this is sometimes not the case for more complex molecules).
Rules of Naming
There are a few easy steps that you can use for chemistry prefixes. First, you need to determine what type of compound it is. Ionic compounds will follow set of rules, and molecular compounds will follow another.
Prefixes for Ionic Compounds
Ionic compounds have the simplest naming convention: nothing gets a prefix. Because these elements have only one oxidation state, you don’t need to specify anything with a prefix. Ba3As2 is simply called “barium arsenide.” Note that arsenic gets the “ide” suffix because it is an element. Ionic compounds with transition metals will contain prefixes to denote oxidation states, but those are not prefixes. For more information, see our tutorial on naming ionic compounds.
Chemistry Prefixes for Molecular compounds
Prefixes in molecular compounds are decided by the number of atoms of each element in the compound. The first step is to count the number of each element. Then, assign a prefix based on the list at the beginning of this article (mono for 1, di for 2, et cetera). Put the two elements together, and don’t forget the “ide” on the second element. To make life easier, you don’t need to include the prefix “mono” for the first element of the two. For example, NO2 would be called nitrogen dioxide, not mononitrogen dioxide. Remember that this rule only applies to the first element of the two.
Examples of Chemistry Prefixes
- CO= carbon monoxide. Each element, carbon and oxygen, has 1 atom. This means that you will use the prefix “mono.” Notice how there is not a “mono” prefix in front of carbon because carbon is the first of the two elements. Next, you should add an “ide” to the end of the compound. Lastly, the full name of this compound would be carbon monoxide.
- S2F2= disulfur difluoride. In this example, sulfur has 2 atoms and fluorine has 2 atoms. This means that we will use the prefix “di” for both sulfur and fluorine. Next, add on an “ide” to the end of fluorine. Once all of these steps are completed, the final name for this compound will be disulfur difluoride.
Try these next 3 examples on your own to see how you do with naming compounds!
3. N2O= dinitrogen monoxide
4. N2O5= dinitrogen pentoxide
5. SnF4= tin (IV) flouride
A note about carbon
Some elements, like carbon, bond differently than most others. The entire field of organic chemistry is devoted to studying the way carbon bonds. Understandably, the rules for naming organic compounds are a lot more complex than for normal, small molecules. For example, we might think to call C2H6 “dicarbon hexahydride,” but in reality it’s called ethane. Don’t worry about those rules for now – it’s just something to keep in the back of your mind!
Applications of Chemistry Prefixes
You use a variety of different compounds in every day life! There is chemistry all around us every day, even if we don’t see it. Visit this website if you would like to learn more about how we use compounds every day!