Question

Locate each of the following elements in the periodic table; give its name and atomic number, and indicate whether it is a metal, metalloid, or nonmetal: (a) \(\mathrm{Hg},(\mathbf{b}) \mathrm{At},(\mathbf{c}) \mathrm{Mo},\) (d) \(\mathrm{W},(\mathbf{e}) \mathrm{Sn},(\mathbf{f}) \mathrm{V},(\mathbf{g}) \mathrm{K}\).

Short answer

(a) Hg, Mercury, atomic number 80, metal. (b) At, Astatine, atomic number 85, metalloid. (c) Mo, Molybdenum, atomic number 42, metal. (d) W, Tungsten, atomic number 74, metal. (e) Sn, Tin, atomic number 50, metal. (f) V, Vanadium, atomic number 23, metal. (g) K, Potassium, atomic number 19, metal.

Step-by-step solution

(a) Identify Hg

Hg, known as Mercury, has an atomic number of 80. It is a metal as it is located in the 'd-block' of the periodic table.

(b) Identify At

At, known as Astatine, has an atomic number of 85. It is classified as a metalloid, as it shares qualities of both metals and non-metals.

(c) Identify Mo

Mo, known as Molybdenum, has an atomic number of 42. It is a metal, also located in the 'd-block' of the periodic table.

(d) Identify W

W, known as Tungsten, has an atomic number of 74. It is a metal, like Mo and Hg, found in the 'd-block' section of the periodic table.

(e) Identify Sn

Sn, known as Tin, has an atomic number of 50. It is a metal found in the 'p-block' of the periodic table, specifically in group 14.

(f) Identify V

V, known as Vanadium, has an atomic number of 23. It is a metal, as it is also located in the 'd-block' section of the periodic table.

(g) Identify K

K, known as Potassium, has an atomic number of 19. It is a metal found in the 's-block' of the periodic table, specifically in group 1 (alkali metals).

Key concepts

Metals

Metals are a group of elements characterized by high electrical and thermal conductivity, malleability, ductility, and a shiny appearance. They are typically found on the left side and in the center of the periodic table.

Here are some key properties of metals:

• Conductivity: Metals are excellent conductors of electricity and heat. This is due to the presence of free-moving electrons in their structure.
• Malleability and Ductility: Metals can be hammered into thin sheets (malleability) or drawn into wires (ductility) without breaking.
• Luster: Metals have a shiny, reflective surface when polished.
• Density and Melting Points: Most metals have high density and melting points.

Metals like Mercury (Hg), Vanadium (V), and Potassium (K) are spread across different blocks of the periodic table, showcasing the versatility of metal properties. For example, Potassium, found in the s-block, is an alkali metal known for its reactivity, while Mercury, a liquid metal at room temperature, is found in the d-block.

Metalloids

Metalloids are elements that have properties intermediate between those of metals and nonmetals. They often appear along a zig-zag line known as the "staircase" in the periodic table.

Here are some typical characteristics of metalloids:

• Semiconductors: Metalloids like Silicon (Si) are widely used in electronics because of their semiconducting properties.
• Intermediate Conductivity: They have electrical conductivity between that of metals and nonmetals, making them useful in various applications.
• Variable Chemical Behavior: Metalloids such as Astatine (At) can behave like metals or nonmetals in different reactions, depending on the circumstances.

Overall, metalloids serve as a bridge between metals and nonmetals, with a unique set of characteristics that are exploited in numerous industrial applications, including computer chip manufacturing and other electronic devices.

Nonmetals

Nonmetals are elements that generally lack the characteristics of metals. They are mostly found on the right side of the periodic table, with diverse properties and applications.

Key features of nonmetals include:

• Poor Conductors: Nonmetals are usually poor conductors of heat and electricity. This is because their electrons do not move as freely as those in metals.
• Brittle in Solid Form: When solid, nonmetals are often brittle and will shatter if struck.
• Varied Physical States: Nonmetals can exist in different states at room temperature—such as gases (e.g., oxygen), liquids (e.g., bromine), and solids (e.g., sulfur).

Due to these properties, nonmetals play essential roles in biological systems, chemical processes, and industrial applications. The diversity of nonmetal states and properties allows them to serve in various capacities, including as essential elements in life-sustaining compounds and reactive agents in chemical manufacturing.