Question

According to IUPAC, what is the designation for each of the following groups indicated by the American convention? (a) Group IA (b) Group IIIA (c) Group VA (d) Group VIIA (e) Group IB (f) Group IIIB (g) Group VB (h) Group VIIB

Short answer

(a) Group 1, (b) Group 13, (c) Group 15, (d) Group 17, (e) Group 11, (f) Group 3, (g) Group 5, (h) Group 7.

Step-by-step solution

Understanding Group Labels

The International Union of Pure and Applied Chemistry (IUPAC) uses a numerical system for labeling groups in the periodic table, which differs from the older American convention that uses Roman numerals and letters (A and B). The American system's A groups include what would typically be referred to as main group elements, while B groups generally refer to transition metals.

Converting Group IA

Group IA in the American system corresponds to Group 1 in the IUPAC system. These elements are known as the alkali metals.

Converting Group IIIA

Group IIIA in the American convention translates to Group 13 in the IUPAC system, which includes elements like boron, aluminum, gallium, etc.

Converting Group VA

In the American system, Group VA corresponds to Group 15 under the IUPAC system. These are often referred to as the pnictogens or nitrogen group.

Converting Group VIIA

Group VIIA as per the American convention matches up with Group 17 in the IUPAC system, known as the halogens.

Converting Group IB

In the American system, Group IB is equivalent to Group 11 in the IUPAC notation. This group contains elements such as copper, silver, and gold, referred to as coinage metals.

Converting Group IIIB

Group IIIB of the American system is labeled as Group 3 in the IUPAC system, which includes elements like scandium, yttrium, and lanthanides.

Converting Group VB

In American convention, Group VB translates to Group 5 in the IUPAC system, containing transition metals such as vanadium and niobium.

Converting Group VIIB

Lastly, Group VIIB in the American system corresponds to Group 7 in the IUPAC notation and includes elements like manganese and rhenium.

Key concepts

Periodic Table Groups

The periodic table is organized into columns known as groups, which help classify elements with similar properties. Each group contains elements that share a common number of valence electrons, contributing to their chemical behavior. The IUPAC system, used internationally, assigns each group a number from 1 to 18. This numbering replaces the older method used by the American convention, which labeled groups with Roman numerals and letters (A and B).
The A groups in the American convention generally correlate with main group elements, including both metals and nonmetals. In contrast, B groups often refer to transition metals, which are located in the central section of the periodic table.

American Convention

The American convention is an older method of labeling groups on the periodic table. This system uses Roman numerals paired with the letters A or B to differentiate between families of elements. Main group elements are typically enclosed within the A categories, whereas the transition metals fall under B categories.
For instance, Group IA contains the alkali metals, while Group IB includes transition metals like copper, recognized for their high electrical conductivity. The American convention gives a familiar label to groups, but the IUPAC system has been adopted to standardize labeling internationally.

Alkali Metals

The alkali metals are located in Group 1 of the IUPAC periodic table, equivalent to Group IA in the American convention. These are highly reactive elements, known for having one valence electron, which they readily lose to form positive ions.
Alkali metals include:

• Lithium (Li)
• Sodium (Na)
• Potassium (K)
• Rubidium (Rb)
• Cesium (Cs)
• Francium (Fr)

This group is characterized by their shiny appearance and the softness of their metals, which can be easily cut with a knife. Due to their high reactivity, these metals must be stored in oil to prevent reactions with moisture in the air.

Halogens

Halogens are found in Group 17 of the IUPAC periodic table, equivalent to Group VIIA in the American convention. They are highly reactive nonmetals, with seven valence electrons, making them eager to gain one electron to complete their outer shell.
Halogens include:

• Fluorine (F)
• Chlorine (Cl)
• Bromine (Br)
• Iodine (I)
• Astatine (At)

These elements play crucial roles in disinfection, manufacturing, and even in the human body. Their reactivity decreases down the group, with fluorine being the most reactive. Often found in combination with other elements, halogens form salts when combined with alkali metals.