Classify each element as an alkali metal, alkaline earth metal, halogen, or noble gas. a. sodium b. iodine c. calcium d. barium e. krypton

Verified step by step guidance

1. Identify the group in the periodic table where each element is located.
2. Recall that alkali metals are found in Group 1 of the periodic table.
3. Recall that alkaline earth metals are found in Group 2 of the periodic table.
4. Recall that halogens are found in Group 17 of the periodic table.
5. Recall that noble gases are found in Group 18 of the periodic table.

Key Concepts

Periodic Table Groups

The periodic table is organized into groups (columns) that categorize elements based on similar properties. Alkali metals (Group 1) are highly reactive and include elements like sodium. Alkaline earth metals (Group 2) are also reactive but less so than alkali metals, while halogens (Group 17) are nonmetals known for their reactivity, and noble gases (Group 18) are inert and do not readily form compounds.

Alkali Metals

Alkali metals are a group of elements found in Group 1 of the periodic table, characterized by having one electron in their outermost shell. This configuration makes them highly reactive, especially with water, and they tend to form +1 cations. Sodium, for example, is a common alkali metal used in various applications, including in the production of chemicals and in batteries.

Halogens and Noble Gases

Halogens are located in Group 17 of the periodic table and are known for their high reactivity, often forming salts when combined with metals. Iodine is a well-known halogen used in antiseptics and as a nutrient. In contrast, noble gases, found in Group 18, are characterized by their complete valence electron shells, making them very stable and unreactive. Krypton is an example of a noble gas, commonly used in lighting and photography.