Question

How many elements are there in the fourth period of the periodic table? Give the name and symbol of each of these elements. Tell whether each is a metal, metalloid, or nonmetal.

Short answer

There are 18 elements in the fourth period, including metals, metalloids, and nonmetals.

Step-by-step solution

Understanding Periods and Elements

The periodic table is organized in rows called periods. Each period corresponds to the number of electron shells in the elements of that row. The fourth period corresponds to elements with electrons filling the fourth shell.

Identifying Elements in the Fourth Period

Identify the elements in the fourth period, which range from potassium (K) to krypton (Kr). These elements are: Potassium (K), Calcium (Ca), Scandium (Sc), Titanium (Ti), Vanadium (V), Chromium (Cr), Manganese (Mn), Iron (Fe), Cobalt (Co), Nickel (Ni), Copper (Cu), Zinc (Zn), Gallium (Ga), Germanium (Ge), Arsenic (As), Selenium (Se), Bromine (Br), and Krypton (Kr).

Classifying Each Element

Classify each element in terms of its category: - **Potassium (K):** Metal - **Calcium (Ca):** Metal - **Scandium (Sc):** Metal - **Titanium (Ti):** Metal - **Vanadium (V):** Metal - **Chromium (Cr):** Metal - **Manganese (Mn):** Metal - **Iron (Fe):** Metal - **Cobalt (Co):** Metal - **Nickel (Ni):** Metal - **Copper (Cu):** Metal - **Zinc (Zn):** Metal - **Gallium (Ga):** Metal - **Germanium (Ge):** Metalloid - **Arsenic (As):** Metalloid - **Selenium (Se):** Nonmetal - **Bromine (Br):** Nonmetal - **Krypton (Kr):** Nonmetal

Counting the Elements

Count the total number of elements listed for the fourth period, including all metals, metalloids, and nonmetals. There are a total of 18 elements in the fourth period.

Key concepts

Periodic Table

The periodic table is like a map of chemical elements. It organizes them in a way that makes it easy to understand and study their properties and relationships. The table is arranged in rows and columns, where each row is called a period and each column is known as a group. The elements are placed based on their atomic number, which is the number of protons in their nucleus.
Each period in the periodic table represents a new electron shell being added to the atoms of the elements in that row. For example, elements in the first period have one electron shell; those in the second period have two shells, and so forth.
The fourth period is particularly notable because it begins to fill the fourth electron shell in the atoms. This arrangement helps in predicting element properties and their chemical behaviors. The periodic table is an essential tool in the field of chemistry for understanding the connections between different elements.

Element Classification

Element classification is a way to categorize all the known elements. In the periodic table, elements are grouped together based on similar properties. These properties are largely influenced by their electron configurations and position in the table.
There are three major classifications for elements: metals, metalloids, and nonmetals. Metals are typically shiny, good conductors of heat and electricity, and are often malleable. Nonmetals have more varied properties but are generally poor conductors of heat and electricity. Metalloids have mixed properties, showing characteristics of both metals and nonmetals.
For example, in the fourth period of the periodic table, elements like potassium (K) and calcium (Ca) are classified as metals due to their typical metallic properties. Germanium (Ge) and arsenic (As) are metalloids, displaying traits of both metals and nonmetals. These classifications help scientists and students predict and understand how different elements will react in various chemical reactions.

Metals, Metalloids, and Nonmetals

Understanding the differences between metals, metalloids, and nonmetals is crucial in the study of chemistry. Each of these groups has distinct properties that influence how the elements behave individually and interact with other elements.

• Metals: These elements are known for their ability to conduct heat and electricity. They are typically malleable, meaning they can be hammered or rolled into thin sheets, and ductile, allowing them to be drawn into wires. In the fourth period, most elements, such as iron (Fe) and copper (Cu), are metals.
• Metalloids: Metalloids are like the bridge between metals and nonmetals. They have mixed properties, making them useful in applications like semiconductors in electronics. In the fourth period, germanium (Ge) and arsenic (As) are examples of metalloids.
• Nonmetals: These elements are usually poor conductors and can exist in various states (gases, liquids, solids) at room temperature. They tend to gain or share electrons when they react. Examples of nonmetals in the fourth period include selenium (Se) and bromine (Br).

Identifying whether an element is a metal, metalloid, or nonmetal helps predict its potential use and its chemical identity and behavior in reactions.