Question

For each of the following elements, write its chemical symbol, determine the name of the group to which it belongs (Table 2.3 ), and indicate whether it is a metal, metalloid, or nonmetal: (a) potassium, (b) iodine, (c) magnesium, (d) argon, (e) sulfur.

Short answer

(a) Potassium: K, Alkali Metals (Group 1), Metal. (b) Iodine: I, Halogens (Group 17), Nonmetal. (c) Magnesium: Mg, Alkaline Earth Metals (Group 2), Metal. (d) Argon: Ar, Noble Gases (Group 18), Nonmetal. (e) Sulfur: S, Chalcogens (Group 16), Nonmetal.

Step-by-step solution

(a) Potassium

Potassium's chemical symbol is 'K'. It belongs to Group 1, also known as Alkali Metals. Potassium is classified as a metal.

(b) Iodine

Iodine's chemical symbol is 'I'. It belongs to Group 17, also known as Halogens. Iodine is classified as a nonmetal.

(c) Magnesium

Magnesium's chemical symbol is 'Mg'. It belongs to Group 2, also known as Alkaline Earth Metals. Magnesium is classified as a metal.

(d) Argon

Argon's chemical symbol is 'Ar'. It belongs to Group 18, also known as Noble Gases. Argon is classified as a nonmetal.

(e) Sulfur

Sulfur's chemical symbol is 'S'. It belongs to Group 16, also known as Chalcogens. Sulfur is classified as a nonmetal.

Key concepts

Chemical Symbols

Chemical symbols are a universal way to represent elements in a concise and standardized format. Each chemical element is assigned a unique symbol, often derived from its English name, though sometimes from its Latin name. These symbols are one or two letters; the first letter is always capitalized, while the second letter is lowercase.

• For example, the chemical symbol for potassium is 'K', which comes from its Latin name 'Kalium'.
• Iodine's chemical symbol is 'I', aligned with its English name.
• Magnesium is symbolized as 'Mg'.
• Argon uses the symbol 'Ar'.
• Lastly, sulfur is represented by 'S'.

By understanding these chemical symbols, scientists and students can communicate elemental information effectively across various languages and regions.

Groups of Elements

In the periodic table, elements are organized into columns called groups. Each group shares certain chemical properties due to similarities in their electron configurations.

• Group 1, or Alkali Metals, includes potassium (K). These elements are highly reactive, especially with water, and are found naturally in compounds rather than in their pure form.
• Magnesium (Mg) is part of Group 2, known as the Alkaline Earth Metals. Elements in this group also show significant reactivity, though less than their Group 1 counterparts.
• Group 17 contains elements called Halogens, which includes iodine (I). Halogens are known for forming salts when they react with metals, and they often occur in nature as diatomic molecules.
• Argon (Ar) belongs to Group 18, the Noble Gases. These elements are incredibly stable due to their full valence electron shells, making them largely non-reactive.
• Sulfur (S) is found in Group 16, known as Chalcogens. These elements tend to form oxides and sulfides, commonly found in minerals.

Recognizing these groups helps in predicting element behavior in chemical reactions.

Metals and Nonmetals Classification

Metals and nonmetals in the periodic table are distinguished based on distinct physical and chemical properties.

• Metals, like potassium (K) and magnesium (Mg), are typically shiny, conductive, and malleable. They tend to lose electrons during chemical reactions, forming positive ions.
• Nonmetals such as iodine (I), argon (Ar), and sulfur (S), may appear as gases, liquids, or brittle solids at room temperature. They are poor conductors of heat and electricity and tend to gain or share electrons in reactions.

Additionally, there is a category known as metalloids, which possess characteristics intermediate between metals and nonmetals, though not directly relevant to our element list here. Understanding this classification system helps predict the behavior of elements in various chemical contexts.