Periodic table group numbers

The elements that form only one cation are the alkali metals (group IA), the alkaline earth metals (group IIA), zinc, cadmium, aluminum, and most often silver. The charge on the ions that these elements form in their compounds is always equal to their periodic table group number (or group number minus 10 in the newest labeling system in the periodic table). 

The charge on every monatomic anion is equal to the group number minus 8 (or 18, if the most modern periodic table group numbering system is used). 

On the basis of the Periodic Table, topics of intermetallic systematics will be presented in the next chapter. In the present chapter the Periodic Table will be revisited and its structure and subdivisions summarized. In relation also to some concepts previously presented, such as electronegativity, Mendeleev number, etc. described in Chapter 2, typical property trends along the Table will be shown. Strictly related concepts, such as Periodic Table group number, average group number and valence-electron number will be considered and used in the description and classification of intermetallic phase families. 

Group number (Section 1.1) The number above a particular column in the periodic table. Group numbers are represented by... 

FOLLOW-UP PROBLEM 2.5 For the following ionic compounds, give the name and periodic table group number of each of the elements present (a) zinc oxide (b) silver bromide (c) lithium chloride (d) aluminum sulfide. 

A Figure 23.22 Variation in atomic radius of transition metals as a function of the periodic table group number. 

Elements are often referred to collectively by their periodic table group number (Group 1 A, Group 2A, and so on). For convenience, however, some element groups have been given special... 

Group number (Section 1.1) The number above a particular column in the periodic table. Group numbers are represented by either an Arabic (1 to 8) or Roman (1 to Vm) numeral followed by the letter A or B. The group number of a second-row element is equal to the number of valence elections in that element... 

Elements are often referred to collectively by their periodic table group number (Group 1 A, Group 2 A, and so on). For convenience, however, some element groups have been given special names. The Group lA elements, with the exception of H (i.e., Li, Na, K, Rb, Cs, and Fr), are called alkali metals, and the... 

In each case, identify the cations and their charges, based on periodic table group numbers or on oxidation states appearing as Roman numerals in names Ba, Ca, and Fe. Then identify the anions and their charges 0 , F, and Combine the cations and anions in the relative numbers required to produce electrically neutral formula units. 

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