Question

Refer to the periodic table and classify each of the following elements as a metal, nonmetal, or semimetal: (a) boron (b) barium (c) beryllium (d) bismuth

Short answer

(a) Semimetal, (b) Metal, (c) Metal, (d) Metal.

Step-by-step solution

Understanding the Periodic Table

The periodic table is divided into several categories: metals, nonmetals, and semimetals (also known as metalloids). Metals are typically on the left side and center of the table, nonmetals are on the right, and semimetals lie between the two with properties of both.

Classifying Boron

Boron is located in group 13 of the periodic table. It is identified as a semimetal because it has properties intermediate between those of metals and nonmetals.

Classifying Barium

Barium is located in group 2, known as the alkaline earth metals. This makes barium a metal as it exhibits characteristics such as conductivity and malleability.

Classifying Beryllium

Beryllium is also in group 2, which places it among the alkaline earth metals. Therefore, beryllium is a metal with similar properties to barium.

Classifying Bismuth

Bismuth is located in group 15 of the periodic table. It is classified as a metal, specifically a post-transition metal, since it exhibits metallic properties.

Key concepts

Metals

Metals are one of the most prevalent types of elements found on the periodic table. Typically, they are located on the left side and center of the table. Metals are known for their shiny appearance and are good conductors of electricity and heat. They are also malleable, meaning they can be hammered or rolled into thin sheets, and ductile, which allows them to be drawn into wires.
Some common properties of metals include:

• High melting and boiling points
• Good electrical and thermal conductivity
• Malleability and ductility
• Tendency to lose electrons, forming cations

In the original exercise, barium and beryllium are examples of metals. Both belong to group 2 of the periodic table, known as the alkaline earth metals, which confirms their metallic nature. Another example from the exercise is bismuth, which, despite being in group 15, is classified as a post-transition metal due to its metallic properties.

Nonmetals

Nonmetals are located on the right side of the periodic table. They possess properties that are quite different from metals. Unlike metals, nonmetals are poor conductors of heat and electricity. They typically have lower melting and boiling points compared to metals and are often brittle when solid. Nonmetals are also more likely to gain electrons during chemical reactions, forming anions.
Here are some characteristic properties of nonmetals:

• Low conductivity of heat and electricity
• Brittleness when solid
• Lower density and melting points relative to metals
• Tendency to gain electrons, forming anions

While the original exercise does not provide an example of a nonmetal, it's crucial to recognize that elements such as nitrogen, oxygen, and sulfur fall under this category, displaying distinct properties associated with nonmetals. Understanding nonmetals' unique characteristics is essential for contrasting them with metals and semimetals.

Semimetals

Semimetals, also known as metalloids, are fascinating elements that have properties intermediate between metals and nonmetals. These elements are typified by their placement along the staircase line that divides metals and nonmetals on the periodic table, stretching between boron and astatine. Their unique properties make semimetals invaluable in various technological applications, especially in electronics and semiconductors.
Key characteristics of semimetals include:

• Variable conductivity of electricity, often enhanced under different conditions
• Brittle, similar to nonmetals, but often have a luster like metals
• Ability to behave as insulators or conductors

In the context of the original exercise, boron is highlighted as a semimetal. Located in group 13, boron showcases both metallic and nonmetallic traits, making it a classical example of a semimetal. This dual nature lends itself to its role in applications such as borosilicate glass and detergents, where both strength and reactivity are required. Understanding semimetals is crucial, as they often bridge the gap in properties between metals and nonmetals.