Question

Using spdf notation, write the electron configurations for atoms of chromium and iron, two of the major components of stainless steel.

Short answer

Chromium: \[ 1s^2 2s^2 2p^6 3s^2 3p^6 3d^5 4s^1 \] Iron: \[ 1s^2 2s^2 2p^6 3s^2 3p^6 3d^6 4s^2 \]

Step-by-step solution

Understand the Basics of Electron Configuration

Electron configuration dictates the distribution of electrons in the orbitals of an atom. It is organized by energy levels (n), sublevel blocks (s, p, d, f), and the number of electrons in each sublevel.

Learn the Aufbau Principle

The Aufbau principle states that electrons fill orbitals starting at the lowest available energy state before filling higher energy states. This principle helps determine the order in which orbitals are filled.

Write the Electron Configuration for Chromium

Chromium has an atomic number of 24, which means it has 24 electrons. Following the Aufbau principle and recognizing the unique configuration of Chromium, its electron configuration is: \[ 1s^2 2s^2 2p^6 3s^2 3p^6 3d^5 4s^1 \]Note that Chromium is an exception to the usual order; it has a more stable configuration with half-filled d orbitals.

Write the Electron Configuration for Iron

Iron has an atomic number of 26, which means it has 26 electrons. Utilizing the Aufbau principle, Iron's electron configuration is: \[ 1s^2 2s^2 2p^6 3s^2 3p^6 3d^6 4s^2 \]This follows the more common order of filling orbitals.

Key concepts

Aufbau principle

The Aufbau principle is a fundamental concept in chemistry that dictates the order in which electrons occupy orbitals. This principle suggests that electrons fill atomic orbitals starting from the lowest energy level and proceed to higher levels. Imagine a multi-story building where electrons are the tenants, and they prefer the ground floor (lowest energy level) before moving to the higher floors (higher energy levels).
The sequence begins with the 1s orbital, then proceeds to 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, and so on. The concept is important because it helps in writing electron configurations for elements, which in turn explain chemical properties. Exceptions occur, for example, with transition metals like chromium and copper, where a more stable configuration can be achieved by moving an electron from an s orbital to a nearby d orbital.

spdf notation

The spdf notation is a shorthand representation used to describe the electron configuration of an atom. Each letter represents a type of orbital, corresponding to different sublevels within an electron shell, namely s, p, d, and f:

• s orbital holds up to 2 electrons.
• p orbital can contain up to 6 electrons.
• d orbital holds up to 10 electrons.
• f orbital accommodates up to 14 electrons.

These orbitals fill according to the Aufbau principle, respecting both energy levels and quantifiable sublevel capacities. For example, the electron configuration of chromium is written using this notation as \( 1s^2 2s^2 2p^6 3s^2 3p^6 3d^5 4s^1 \). This notation not only reflects the distribution of electrons among different orbitals but also illustrates the stability of electron configuration through either half or fully filled orbitals.

transition metals

Transition metals are elements found in the d-block of the periodic table. They are known for their ability to form various oxidation states, complex ions, and colored compounds. The electron configuration of these metals typically includes partially filled d orbitals. This is a key factor that contributes to the unique properties of these elements.
Some common characteristics of transition metals include:

• High melting and boiling points.
• Good conductors of electricity and heat.
• Exhibit magnetic properties.
• Can display catalytic abilities in industrial processes.

The electron configurations of transition metals often include exceptions to the standard filling order as seen in chromium \( (3d^5 4s^1) \) and copper \( (3d^{10} 4s^1) \).

stainless steel

Stainless steel is a corrosion-resistant iron alloy that includes a minimum chromium content of approximately 10.5%. This content of chromium induces the formation of a passive layer of chromium oxide, making the material resistant to oxidation and corrosion. Elements like chromium and iron are fundamental in creating stainless steel, each with specific electron configurations contributing to their unique properties. For example, chromium's electron configuration \(1s^2 2s^2 2p^6 3s^2 3p^6 3d^5 4s^1\) is essential for this alloy due to its ability to form a protective oxide layer.
Stainless steel is favored for its:

• Durability and tensile strength.
• Resistance to rust and stains, making it ideal for harsh environments.
• Low maintenance and long-lasting characteristics.
• Appearance, which often requires minimal polishing.

This makes stainless steel a crucial material in various industries, including construction, automotive, and even in kitchenware.