Question

Refer to the periodic table and classify each of the following elements as a metal, nonmetal, or semimetal: (a) argon (b) antimony (c) arsenic (d) astatine

Short answer

(a) Nonmetal; (b) Semimetal; (c) Semimetal; (d) Nonmetal.

Step-by-step solution

Locate Argon on the Periodic Table

Argon is located in Group 18 of the periodic table. Group 18 is known as the noble gases group.

Determine the Classification of Argon

Noble gases, including argon, are classified as nonmetals because they are gases at room temperature and are not metals or metalloids.

Locate Antimony on the Periodic Table

Antimony is located in group 15 on the periodic table, and is often placed on the boundary between metals and nonmetals.

Determine the Classification of Antimony

Antimony is classified as a semimetal (or metalloid) because it exhibits properties of both metals and nonmetals.

Locate Arsenic on the Periodic Table

Arsenic is also found in group 15 of the periodic table.

Determine the Classification of Arsenic

Like antimony, arsenic is classified as a semimetal (or metalloid) due to its intermediate properties.

Locate Astatine on the Periodic Table

Astatine is found in Group 17 of the periodic table, which contains the halogens.

Determine the Classification of Astatine

Astatine is classified as a nonmetal, although it also shows some metal-like properties; however, it is commonly considered a nonmetal.

Key concepts

Metals

Metals are elements that are generally found on the left side and towards the bottom of the periodic table. They have distinct characteristics that make them quite useful in various applications, both industrial and everyday. Metals are known for their high electrical and thermal conductivity, meaning they can easily conduct electricity and heat. This property makes them essential in making electrical wiring and components.

Another hallmark property of metals is their malleability and ductility. Malleability refers to a metal's ability to be hammered into thin sheets without breaking, while ductility means it can be stretched into wires. The combination of these traits allows for versatile uses in construction and manufacturing.

Furthermore, metals typically exhibit a lustrous appearance, meaning they have a shiny surface that reflects light. Most metals are solid at room temperature, with mercury being a notable exception. Common examples of metals include iron, copper, and gold, each playing critical roles in our daily lives.

Nonmetals

Nonmetals are found on the right side of the periodic table, with properties that contrast with those of metals. They tend to have lower densities compared to metals and are generally poor conductors of heat and electricity.

One of the key characteristics of nonmetals is their states at room temperature. While metals are mostly solid, nonmetals can exist in various states: solid, liquid, or gas. For example, oxygen is a gas, bromine is a liquid, and carbon is a solid at room temperature. This variety makes nonmetals crucial in chemical reactions where different states are required.

Nonmetals are not shiny and usually have a dull appearance. They are also more brittle than metals, meaning they can break or shatter easily if force is applied. Nonmetals also have high electronegativities, allowing them to attract electrons when forming chemical bonds. Common nonmetals include carbon, nitrogen, and chlorine, each with its own essential roles in biology and industry.

Semimetals

Semimetals, also known as metalloids, are elements found along the dividing line between metals and nonmetals on the periodic table. These elements display properties of both metals and nonmetals, making them unique and versatile in various technological applications.

One major trait of semimetals is their ability to conduct electricity, but not as efficiently as metals. This property classifies them as semiconductors, which are critical materials in the electronics industry for making components like transistors and diodes.

Semimetals usually have a lustrous appearance like metals but are brittle rather than ductile. They can break more easily under force and do not easily deform. Elements like silicon and arsenic are classic examples of semimetals. Silicon, in particular, is the backbone of modern electronics, found in microchips and solar panels.

With a unique blend of metal and nonmetal characteristics, semimetals play a significant role in advancing technology, highlighting the importance of understanding each group's distinctive properties.