Which of the following elements is not a alkali metal?

Which of the following elements is not a alkali metal?

• A. Sodium
• B. Lithium
• C. Bromine
• D. Rubidium

Answer: (C)

In the context of the periodic table, alkali metals are defined as the elements found in Group 1 (Group IA) of the periodic table. These elements are characterized by having one electron in their outermost shell, which they readily lose to form positive ions with a charge of +1. This group includes sodium, lithium, and rubidium, all of which exhibit similar chemical properties due to their electron configuration. Bromine, on the other hand, is located in Group 17 (Group VIIA) of the periodic table and is classified as a halogen rather than an alkali metal. Halogens have seven electrons in their outer shell and tend to gain an electron to achieve a stable octet, forming ions with a charge of -1. Therefore, bromine does not share the characteristics or reactivity of alkali metals, making it the correct answer to identify as not being part of this group. Understanding these group classifications helps in recognizing the chemical behavior of different elements. Alkali metals are highly reactive, especially with water, forming hydroxides and hydrogen gas, while halogens, including bromine, are typically more reactive with metals to form salts.

In the context of the periodic table, alkali metals are defined as the elements found in Group 1 (Group IA) of the periodic table. These elements are characterized by having one electron in their outermost shell, which they readily lose to form positive ions with a charge of +1. This group includes sodium, lithium, and rubidium, all of which exhibit similar chemical properties due to their electron configuration.

Bromine, on the other hand, is located in Group 17 (Group VIIA) of the periodic table and is classified as a halogen rather than an alkali metal. Halogens have seven electrons in their outer shell and tend to gain an electron to achieve a stable octet, forming ions with a charge of -1. Therefore, bromine does not share the characteristics or reactivity of alkali metals, making it the correct answer to identify as not being part of this group.

Understanding these group classifications helps in recognizing the chemical behavior of different elements. Alkali metals are highly reactive, especially with water, forming hydroxides and hydrogen gas, while halogens, including bromine, are typically more reactive with metals to form salts.