Question

An element has completely filled \(n=1\) and \(n=2\) shells and has six electrons in the \(n=3\) shell. Identify the element and its major group (i.e., main group, transition, etc.). Is it a metal or a nonmetal? Identify the orbital in which the last electron is found.

Short answer

The element is Sulfur, a Group 16 nonmetal, and the last electron is in the 3p orbital.

Step-by-step solution

Understanding Electron Configuration Requirements

To solve the problem, we need to consider the electron configuration: "completely filled \(n=1\) and \(n=2\) shells and has six electrons in the \(n=3\) shell." The completely filled \(n=1\) shell has 2 electrons (in the 1s orbital). The completely filled \(n=2\) shell has 8 electrons (in the 2s and 2p orbitals). Now, let's consider the remaining 6 electrons in the \(n=3\) shell.

Electron Configuration of n=3 Shell

The electron configuration of the \(n=3\) shell starts with \(3s^2\), follows with \(3p^6\) for filling completely. However, since there are only 6 electrons in the \(n=3\) shell from the problem statement, once \(3s^2\) and \(3p^4\) are filled (4 electrons in \(3p\) since it can hold a total of 6 electrons), we find that the electron configuration for \(n=3\) is \(3s^2\ 3p^4\).

Identification of the Element

The total electrons calculated are: 2 (\(n=1\)) + 8 (\(n=2\)) + 6 (\(n=3\)) = 16 electrons. Thus, the atomic number of the element is 16. The element with atomic number 16 is Sulfur (S).

Determining the Major Group and Type of Element

Sulfur is located in Group 16 in the periodic table. It belongs to the main group, specifically the chalcogens. Sulfur is a nonmetal.

Identifying the Last Electron Orbital

Since the \(n=3\) shell reaches a configuration of \(3s^2\ 3p^4\), the last electron is found in the \(3p\) orbital.

Key concepts

Sulfur

Sulfur is an essential nonmetallic element found in nature with the atomic number 16. Recognized by its symbol "S," sulfur is a part of many important compounds, including sulfuric acid. In its most basic form, sulfur is a bright yellow solid. It is essential for life as it is a component of certain amino acids and vitamins. Sulfur's presence is also notable in the structure of proteins, playing a key role in maintaining proper cellular function.
Sulfur has a characteristic sulfur smell which most people recognize in the form of rotten eggs or volcanic eruptions. Despite its sometimes unpleasant odor, it's vital for various biological processes and is used commercially in fertilizers and other products.
The electron configuration of sulfur is particularly important in chemical reactions, as it determines how sulfur atoms will interact with other atoms to form compounds.

Periodic Table Groups

The periodic table is organized into several columns known as groups. Each group of elements shares certain chemical properties. There are 18 groups in the standard periodic table. Elements in the same group typically have similar valence electron configurations, which explains their similar chemical behaviors.
Sulfur belongs to Group 16, often referred to as the chalcogens, along with other elements such as oxygen, selenium, and tellurium. This group is known for containing nonmetals, which tend to form -2 anions when reacting with metals.
Group 16 elements are known for their ability to form diverse oxidation states, making them very versatile in chemical reactions. They are also vital for various biological and environmental processes, particularly in the formation of sulfide and sulfate minerals.

Nonmetals

Nonmetals are characterized by their lack of metallic properties such as luster, conductivity, and malleability. Instead, they are often brittle when solid and display a wide range of colors. In their usual state, nonmetals are poor conductors of heat and electricity. This is due to their high electronegativity, which means they tend to gain electrons when they react.
These elements often form covalent bonds by sharing electrons with other nonmetals. Sulfur, as a nonmetal, typically gains electrons to form sulfide (\(S^{2-}\)) ions during chemical reactions.
Nonmetals, including sulfur, are found in the upper right corner of the periodic table. They play crucial roles in both organic and inorganic chemistry. For instance, nonmetals make up the backbone of DNA, proteins, and many other vital biological molecules. Their roles in life and the environment cannot be overstated, providing the building blocks for all organic matter.