Question

For each of the following elements, use the tables on the inside cover of this book to give the chemical symbol, atomic number, and group number of each element, and to specify whether the element is a metal, nonmetal, or metalloid. a. lithium b. arsenic c. radon d. radium e. germanium

Short answer

a. Lithium (Li) - atomic number 3, Group 1, metal. b. Arsenic (As) - atomic number 33, Group 15, metalloid. c. Radon (Rn) - atomic number 86, Group 18, nonmetal. d. Radium (Ra) - atomic number 88, Group 2, metal. e. Germanium (Ge) - atomic number 32, Group 14, metalloid.

Step-by-step solution

a. Lithium

Lithium can be found in the periodic table with the chemical symbol "Li". It has an atomic number of 3 and belongs to Group 1, which is known as the alkali metals. Therefore, lithium is classified as a metal.

b. Arsenic

Arsenic can be found in the periodic table with the chemical symbol "As". It has an atomic number of 33 and belongs to Group 15. Arsenic is a metalloid, as it has properties common to both metals and nonmetals.

c. Radon

Radon can be found in the periodic table with the chemical symbol "Rn". It has an atomic number of 86 and belongs to Group 18, which is known as the noble gases. Radon is classified as a nonmetal, as all noble gases are nonmetals.

d. Radium

Radium can be found in the periodic table with the chemical symbol "Ra". It has an atomic number of 88 and belongs to Group 2, which is known as the alkaline earth metals. As part of this group, radium is classified as a metal.

e. Germanium

Germanium can be found in the periodic table with the chemical symbol "Ge". It has an atomic number of 32 and belongs to Group 14. Like arsenic, germanium is also a metalloid, as it has properties of both metals and nonmetals.

Key concepts

Chemical Symbol

The chemical symbol is a one or two-letter abbreviation derived from the element's name, often in Latin. It serves as a universal shorthand for identifying chemical elements on the periodic table. Each element has a unique chemical symbol that simplifies scientific communication. For example:

• Lithium is represented as 'Li'.
• Arsenic is represented as 'As'.
• Germanium is represented as 'Ge'.

These symbols enable easy identification and help in writing chemical equations and formulas efficiently.

Atomic Number

The atomic number of an element is a fundamental property that signifies the number of protons in the nucleus of an atom. It determines the identity of an element and its position on the periodic table. The periodic table is organized in increasing order according to atomic numbers:

• For instance, lithium has an atomic number of 3, meaning it has 3 protons.
• Radon with an atomic number of 86 has 86 protons.

The atomic number also dictates the chemical behavior of the element, influencing its reactivity and bonding with other elements.

Metals

Metals are one of the primary classifications of elements on the periodic table. They are typically characterized by their ability to conduct electricity and heat, malleability, ductility, and a shiny appearance. Most metals are found on the left side of the periodic table. Metals often lose electrons to form positive ions in chemical reactions. Key features include:

• Lithium and radium are metals, as lithium belongs to the alkali metals and radium to the alkaline earth metals.
• Both are good conductors of electricity and have a metallic shine.

Metals are crucial in many industries and everyday products, ranging from construction to electronics.

Nonmetals

Nonmetals are elements found primarily on the right side of the periodic table, with distinct features from metals. They are usually not shiny, have lower densities, and are poor conductors of heat and electricity. Nonmetals tend to gain or share electrons in chemical reactions. Radon is a classic example of a nonmetal:

• As a noble gas, radon is colorless, odorless, and chemically inert, making it distinct from typical nonmetals.

Nonmetals play vital roles in both organic and inorganic chemistry and are essential for life, with elements like oxygen and carbon being nonmetallic.

Metalloids

Metalloids display properties that are intermediate between metals and nonmetals, earning their classification based on the shared qualities they exhibit. They are located along the staircase line on the periodic table. These elements are semiconductors, an essential property for the electronics industry. Arsenic and germanium are examples of metalloids:

• Arsenic possesses both metallic luster and brittle nonmetallic characteristics.
• Germanium is used extensively in semiconductors and exhibits both metallic and nonmetallic behaviors.

The unique dual characteristics of metalloids make them invaluable in various scientific and technological fields.