Problem 161 - Introductory Chemistry Atoms First

Question

Which is the correct ground-state electron configuration for antimony, Sb? (a) \(1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{10} 4 s^{2} 4 p^{6} 4 d^{10} 5 s^{2} 5 d^{3}\) (b) \(1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{10} 4 s^{2} 4 p^{6} 4 d^{10} 5 s^{2} 5 p^{3}\) (c) \(1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{2} 3 d^{10} 4 p^{6} 5 s^{2} 4 d^{10} 5 p^{4}\) (d) \(1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{2} 3 d^{10} 4 p^{6} 5 s^{2} 5 p^{3}\) (e) \(1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{2} 3 d^{10} 4 p^{6} 5 s^{2} 4 f^{3}\)

Step-by-Step Solution

Answer

The correct ground-state electron configuration for antimony (Sb) is: \(1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 3d^{10} 4s^{2} 4p^{6} 4d^{10} 5s^{2} 5p^{3}\).

Step 1: Determine the atomic number of Antimony (Sb)

By consulting a periodic table, we find out that the atomic number of antimony, Sb, is 51. This means that an antimony atom has a total of 51 electrons. Step 2: Begin creating the electron configuration

Step 2: Write the electron configuration step by step

Using the Aufbau principle, electrons fill the orbitals in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s. A step-by-step guide to filling up orbitals for Sb (51 electrons): 1s^2 (2 electrons) 2s^2 (2 electrons) 2p^6 (6 electrons) 3s^2 (2 electrons) 3p^6 (6 electrons) 4s^2 (2 electrons) 3d^10 (10 electrons) 4p^6 (6 electrons) 5s^2 (2 electrons) 4d^10 (10 electrons) 5p^3 (3 electrons) Step 3: Compare the electron configuration with given choices

Step 3: Compare your derived electron configuration with the given options

Compare the electron configuration obtained in step 2: 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^3 with the given configurations (a), (b), (c), (d), and (e), you'll find that our electron configuration matches option (b). (b) 1s^2 2s^2 2p^6 3s^2 3p^6 3d^10 4s^2 4p^6 4d^10 5s^2 5p^3 So, the correct ground-state electron configuration for antimony, Sb, is (b).

Key Concepts

Antimony

Antimony is a fascinating element and part of the periodic table that has an atomic number of 51. This means an antimony atom contains 51 electrons. The symbol for antimony is 'Sb', derived from its Latin name, stibium. Historically, antimony has been used in various ways, such as in cosmetics and medicine.

In terms of its atomic structure, understanding antimony’s electron configuration is vital because it reveals how the electrons are organized in energy levels around the nucleus. This distribution of electrons plays a crucial role in the chemical behavior and reactions that antimony can participate in.

When discussing elements like antimony, a clear grasp of electron configurations helps us predict and explain a variety of chemical properties, thus making it a key area of study.

Periodic Table

The periodic table is a fundamental tool for chemists and anyone studying chemistry. It organizes all known chemical elements in a structured way, based on their atomic number, electron configurations, and recurring chemical properties.

The table is divided into periods (rows) and groups (columns). Each element is placed according to its atomic number, which signifies the number of protons—and, thus, in a neutral atom, the number of electrons—the atom possesses.

Antimony, with an atomic number of 51, is located in period 5 and group 15 of the periodic table. This position tells us that antimony is a metalloid, possessing properties of both metals and non-metals. Its placement also helps in visualizing the electron configuration pattern, making it easier to apply principles like Aufbau when determining electron arrangements.

Recognizing the position of elements on the periodic table can help predict an element's properties and behaviors, both physical and chemical.

Aufbau Principle

The Aufbau principle is essential for understanding how electrons fill atomic orbitals. In simple terms, this principle states that electrons occupy the lowest energy orbitals first before moving to higher ones.

The sequence most commonly followed is:

• 1s
• 2s, 2p
• 3s, 3p, 3d
• 4s, 4p, 4d
• 5s, 5p
• 6s, 4f
• 5d, 6p
• 7s

These patterns reflect the energies of the sublevels and dictate their filling order.

For antimony, using the Aufbau principle means that its 51 electrons will fill the orbitals in ascending energy levels, resulting in the correct ground-state electron configuration. It starts with 1s and fills up to 5p, following the aforementioned order and considering any energy overlaps between levels.

Mastery of the Aufbau principle allows anyone studying chemistry to visualize how electrons are distributed across an atom’s orbitals, supporting all subsequent chemical analysis.

Ground-state

When we speak of an atom being in its ground-state, we refer to the situation where all its electrons are in the lowest possible energy levels available. This is the most stable arrangement of electrons within an atom.

For antimony, determining the ground-state electron configuration involves arranging all 51 electrons in a way that results in the lowest energy state possible. The configuration that achieves this is:

• 1s^2 2s^2 2p^6 3s^2 3p^6
• 4s^2 3d^10 4p^6 5s^2
• 4d^10 5p^3

This layout reflects the filling orders dictated by the Aufbau principle.

Identifying the ground-state electron configuration is crucial because it defines the starting point from which atoms will interact in chemical processes. It implies that any excitation or energy input can move electrons to higher energy states, which then postents reactions and bonding opportunities with other atoms.