Write the correct formula for an ionic compound. Recognize polyatomic ions in chemical formulas. Ionic compounds do not exist as molecules.
This is because the number of electrons negative in charge is equal to the number of protons positive in charge. The overall charge on the atom is zero, because the magnitude of the negative charge is the same as the magnitude of the positive charge. This one-to-one ratio of charges is not, however, the most common state for many elements.
Deviations from this ratio result in charged particles called ions. Throughout nature, things that are high in energy tend to move toward lower energy states. Lower energy configurations are more stable, so things are naturally drawn toward them.
For atoms, these lower energy states are represented by the noble gas elements. These elements have electron configurations characterized by full s and p subshells. This makes them stable and unreactive. They are already at a low energy state, so they tend to stay as they are.
The elements in the other groups have subshells that are not full, so they are unstable when compared to the noble gases.
This instability drives them toward the lower energy states represented by the noble gases that are nearby in the periodic table.
Polyatomic Ions- are molecules made up of 2 or more atoms that are considered an ionic group, that is, a molecule with a charge. These form compounds that will contain both ionic and covalent bonds. Writing Chemical formula with polyatomic groups 1. Use the Periodic table to determine the combining powers of single elements. Use Table 1 to determine the valency of the major polyatomic groups. Table 1: The Combining Power of Polyatomic Ions Combining power of 1 Combining power of 2 Combining power of 3 Ammonium ion, NH 4 + . Teachers should be familiar with naming and formula writing for ionic compounds. Students should be familiar with periodic table classifications including: metals, nonmetals, transition metals, main-group elements, s, p, d, f blocks, and chemical formulas.
One way is the transfer of electrons between two atoms until both atoms have octets. Because some atoms will lose electrons and some atoms will gain electrons, there is no overall change in the number of electrons, but with the transfer of electrons the individual atoms acquire a nonzero electric charge.
Those that lose electrons become positively charged, and those that gain electrons become negatively charged. Recall that atoms carrying positive or negative charges are called ions.
If an atom has gained one or more electrons, it is negatively charged and is called an anion. If an atom has lost one or more electrons, it is positively charged and is called a cation. Because opposite charges attract while like charges repelthese oppositely charged ions attract each other, forming ionic bonds.
The resulting compounds are called ionic compounds.
The second way for an atom to obtain an octet of electrons is by sharing electrons with another atom. These shared electrons simultaneously occupy the outermost shell of both atoms. The bond made by electron sharing is called a covalent bond. At the end of chapter 2, we learned how to draw the electron dot symbols to represent the valence electrons for each of the elemental families.
This skill will be instrumental in learning about ions and ionic bonding. Looking at Figure 3. The electron dot symbol for the Nobel Gas family clearly indicates that the valence electron shell is completely full with an octet of electrons.
If you look at the other families, you can see how many electrons they will need to gain or lose to reach the octet state. Above, we noted that elements are the most stable when they can reach the octet state.
However, it should also be noted that housing excessively high negative or positive charge is unfavorable. Thus, elements will reach the octet state and also maintain the lowest charge possible. You will note that for the IA, IIA, IIIA and transition metals groups, it is more economical to lose electrons electrons from their valence shells to reach the octet state, rather than to gain electrons.
Some atoms, like carbon, are directly in the middle. The remaining sections of this chapter will focus on the formation of ions and the resulting ionic compounds.
A Depiction of St. B In many high voltage applications plasma ionization is an unwanted side effect. Shown is a long exposure photograph of corona discharge on an insulator string of a kV overhead power line.
This type of plasma discharge represent a significant power loss for electric utilities. Photograph depicted in a A by: Unknown Author Photograph depicted in a B by: Elements on the left side of the periodic table, metals, lose the electrons necessary to reach the electron configuration of the nearest noble gas.
Transition elements can vary in how they move toward lower energy configurations.
They lose one electron upon ionization, moving into the electron configuration of the previous noble gas. For example as shown in Figure 3. The sodium ion has one fewer electron than it has protons, so it has a single positive charge and is called a cation.Ionic compounds are (usually) formed when a metal reacts with a nonmetal (or a polyatomic ion).
Covalent compounds are formed when two nonmetals react with each other. Since hydrogen is a nonmetal, binary compounds containing hydrogen are also usually covalent compounds.
Naming polyatomic ionic compounds is the tricky one, and there are several rules depending on the different ions involved. Naming Ionic Compounds: Simple Binary, Transition Metal & Polyatomic. Writing Formulas & Names for Polyatomic Compounds INFORMATION Polyatomic ions, Writing Formulas & Names for Polyatomic Ionic Compounds / 2 Writing Formulas for Polyatomic Compounds The formula writing and naming of polyatomic ionic compounds is similar to the process for binary.
Worksheet Writing and Naming Ionic Compounds with Polyatomic Ions and Transition Metals Section A Write the name of the ionic compounds containing polyatomic ions (BE CAREFUL TRANSITION METALS MAY HAVE ROMAN NUMERALS and NICKNAMES) 1. Pb3 Answer Key Worksheet Naming and Writing Ionic Compounds with .
Jul 27, · Chemistry is one of the chemicals, ionic compounds where the United ionic bonds ions in the structure of the formula of metal cations in general, positive ion and a polyatomic anion is the negatively charged.
Rules for Naming Ionic Compounds Containing Polyatomic Ions: Polyatomic ions are ions which consist of more than one atom. For example, nitrate ion, NO 3-, contains one nitrogen atom and three oxygen leslutinsduphoenix.com atoms in a polyatomic ion are usually covalently bonded to one another, and therefore stay together as a single, charged unit.