2 7: Nomenclature of Ionic, Covalent, and Acid Compounds Chemistry LibreTexts

Al is a Type I monatomic ion, no Roman Numeral is needed since the charge does not change. Change the oxygen ending to the -ide ending for the anion. Using the Principle of Charge Neutrality (section 2.6.6) and knowing the charge of the ions allows you to determine the formula.

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So you do not need to state the number of cations and anions, you only need to state what they are (and what their charge is). You then figure the formula based on the lowest whole number ratio of cations to anions that produces a neutral formula. Organic compounds have functional groups, and many organic anions are based on the carboxylate group. This video helps you use that to remember the formula of polyatomic ions like acetate, phthlate and oxylate. Compounds that consist of a nonmetal covalently bonded to a nonmetal are commonly known as Molecular Compounds, where the element with the positive oxidation state is written first.

Molecular Compounds: Nonmetals and Nonmetals

Earn free shipping when you order 2 or more bottles of A2X. These are the key concepts you need to understand to accurately answer the question.

Chemical Reactions

Zinc and Cadmium (group 2B) form +2 cations like the group 1B alkaline earth metals. The lighter Group 3A metals (Aluminum, Galium and Indium), along with Scandium and Yttrium lose 3 electrons to form +3 cations. All the remaining transition metals form multiple charged ions (iron for example, forms Fe+2 and Fe+3 and thus has multiple charge states). The first question we ask is if the compound is ionic or covalent?

Chemical Analysis

As we have seen in the previous section, there are two types of monatomic ions, those of elements that form only one charge state, and those that can form multiple charged states. The anions are all of the first type, and gain electrons until they have the same number as the nearest noble gas. total revenue formula But metals form cations by losing electrons, and some metals form only one stable cation, while others can form many.

We will start with binary ionic, which are between monatomic anions and cations. We note that there are two types of metals, those that have only 1 charge (Type 1), and those that can have more than one stable charge. Finally, polyatomic ions often form which are covalently bonded atoms where the total number of protons is not equal to the total number of electrons.

We will understand later this semester that as you go down a family or group of the periodic table, the volume of the atoms increases. The reason the second row nonmetals are an exception can best be understood by their small size (how are you going to get 4 oxygens around a small fluorine)? So on an exam at the freshmen level, I would probably treat them as if they follow the same trend as chlorine, because that is the schema you are learning. Some of the metals form very common ions which have latin names that are in common use, and you need to be familiar with those in the following table. Note, “-ic” stands for the higher oxidation state (charge), and “-ous” stands for the lower oxidation state. We use the Principle of Charge Neutrality, that is, for an ionic compound to be stable its chemical formula MUST BE NEUTRAL.

Alkali metals (Group 1A) lose one electron to becomes isoelectronic to a noble gas. Alkaline earths (Group 2A) lose two electrons and many of the compounds , silver (group 1B) only forms +1 cations. Alkaline earths lose two electrons (becoming isoelectronic to a noble gas) and many of the group IIIA only form cations +3 charge.

For simplicity, we will call metals that form only one (invariant) charge state to be Type I and those that form variable charge states to be type 2. It is probably easiest to identify the Type 1 and consider others to be Type 2. There are some transition metals that form only one stable ion. Silver (Group 1B) forms a +1 cation like the 1A alkali metals.