Which ion does al typically form

When something loses electrons we say that it has been oxidised. When something gains electrons, we say it has been reduced. So in ionic bonding, the metals are oxidised and the non-metals are reduced.

Forming ions Ions are electrically charged particles formed when atoms lose or gain electrons. Positively charged sodium and aluminium ions. Negatively charged oxide and chloride ions. Electrons, however, can be added to atoms by transfer from other atoms, lost by transfer to other atoms, or shared with other atoms. The transfer and sharing of electrons among atoms govern the chemistry of the elements. During the formation of some compounds, atoms gain or lose electrons, and form electrically charged particles called ions Figure 1.

Figure 1. You can use the periodic table to predict whether an atom will form an anion or a cation, and you can often predict the charge of the resulting ion. Atoms of many main-group metals lose enough electrons to leave them with the same number of electrons as an atom of the preceding noble gas. For example, a neutral calcium atom, with 20 protons and 20 electrons, readily loses two electrons. When atoms of nonmetal elements form ions, they generally gain enough electrons to give them the same number of electrons as an atom of the next noble gas in the periodic table.

For example, the neutral bromine atom, with 35 protons and 35 electrons, can gain one electron to provide it with 36 electrons. A discussion of the theory supporting the favored status of noble gas electron numbers reflected in these predictive rules for ion formation is provided in a later chapter of this text.

Note the usefulness of the periodic table in predicting likely ion formation and charge Figure 2. Moving from the far left to the right on the periodic table, main-group elements tend to form cations with a charge equal to the group number. Moving from the far right to the left on the periodic table, elements often form anions with a negative charge equal to the number of groups moved left from the noble gases.

This trend can be used as a guide in many cases, but its predictive value decreases when moving toward the center of the periodic table. In fact, transition metals and some other metals often exhibit variable charges that are not predictable by their location in the table.

Figure 2. Some elements exhibit a regular pattern of ionic charge when they form ions. An ion found in some compounds used as antiperspirants contains 13 protons and 10 electrons. What is its symbol? Because the number of protons remains unchanged when an atom forms an ion, the atomic number of the element must be Knowing this lets us use the periodic table to identify the element as Al aluminum.

The Al atom has lost three electrons and thus has three more positive charges 13 than it has electrons Magnesium and nitrogen react to form an ionic compound. Predict which forms an anion, which forms a cation, and the charges of each ion. Write the symbol for each ion and name them.

Metals form positive ions cations. Similarly, it is easier for oxygen to gain 2 electrons instead of loosing 6 electrons:.

Symbolically, we can represent this oxygen ion as O The Periodic Table can be used to help predict how many electrons there are in the outermost shell, and hence what type of ion they will form. Here is the same chart from the previous page, but with some additional information added to it:. The black numbers above represent the number of electrons in the outer shell. Notice that each column has more electrons in the outermost shell as you go to the right, and that the last row headed by He or Helium has a full outer shell.

Elements with a full outer shell do not form ions. The yellow section, labeled "Transition Elements" are elements that tend to lose electrons from shells other than the outermost shell and form positive ions.

Understanding why there are different ions of iron is complex and beyond the scope of this course. However, you should be able to determine the ionic state of atoms from the other groups using a Periodic Table. What ion would a Chlorine Cl atom form?