Problem 88 - Chemistry

Question

Use the Aufbau principle to obtain the ground-state electron configuration of technetium.

Step-by-Step Solution

Answer

The ground-state electron configuration of Technetium is 1s\(^2\), 2s\(^2\), 2p\(^6\), 3s\(^2\), 3p\(^6\), 4s\(^2\), 3d\(^{10}\), 4p\(^6\), 5s\(^2\), 4d\(^5\).

Step 1: Understanding Technetium's Atomic Number

Technetium is the 43rd element on the Periodic table, so it has 43 electrons in its ground state.

Step 2: Aufbau Principle Application

The Aufbau principle stipulates that lower energy orbitals are filled before higher energy orbitals. The order for filling is 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, and 6d. Using this sequence, fill up the energy levels until there are no more electrons left.

Step 3: Implementation For Technetium

Follow the order of the Aufbau principle until all 43 electrons are used up. The electron configuration becomes: 1s\(^2\), 2s\(^2\), 2p\(^6\), 3s\(^2\), 3p\(^6\), 4s\(^2\), 3d\(^{10}\), 4p\(^6\), 5s\(^2\), 4d\(^5\).

Key Concepts

Aufbau Principle

The Aufbau principle is a fundamental guideline for writing electron configurations in chemistry. It helps us understand the sequence in which atomic orbitals are filled with electrons.
This principle comes from the German word "Aufbau," meaning "building up" or "construction."
According to this concept, electrons occupy the lowest energy orbitals first before moving to higher ones.

• Starting from the lowest energy level and moving step-by-step to higher ones is key.
• The sequence used is based on increasing energy levels: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, etc.
• This order helps to predict how electrons are arranged around an atom, which impacts an element's chemical properties.

For Technetium, with 43 electrons, we use the order from the Aufbau principle to compose its electron configuration. This process involves filling the orbitals systematically until we reach the total electron count of Technetium.

Technetium

Technetium is a unique element found in the middle of the periodic table. It is represented by the symbol Tc and has an atomic number of 43. This makes it a part of the transition metals group.
Transition metals are known for their versatility and ability to form various compounds.
Despite being widely used in scientific fields, technetium is not found naturally in the Earth's crust in large amounts. It is typically a byproduct of nuclear reactions.

• Technetium is essential in several applications, especially in the medical field for imaging and diagnostic procedures.
• Its electron configuration and unique properties come from its position in the periodic table.
• The knowledge of its electron configuration helps scientists utilize technetium effectively in various fields.

For students, knowing Technetium's atomic structure helps tie together concepts of electron configuration and its practical impacts.

Atomic Number

The atomic number is an essential concept in chemistry representing the number of protons found in the nucleus of an atom of an element. This number is unique to each element and determines its identity on the periodic table.
For example, Technetium has the atomic number 43, meaning it has 43 protons. This directly correlates to the number of electrons in a neutral atom, helping to establish its electron configuration.

• Atomic number increases progressively as you move through the periodic table.
• It helps with the determination of electron configuration, defining how electrons fill available orbitals.
• Atomic number is used to predict chemical properties and reactivity.

Understanding the atomic number offers a clear pathway to comprehending more about how elements behave and interact chemically, solidifying the building blocks of chemistry knowledge.