Problem 31 - Chemistry: Principles and Reactions

Question

Write the abbreviated ground state electron configuration for (a) \(\mathrm{P}\) (b) As (c) Sn (d) Zr (e) Al

Step-by-Step Solution

Answer

Question: Write the abbreviated ground state electron configurations for the following elements using the noble gas notation: (a) Phosphorus (P) (b) Arsenic (As) (c) Tin (Sn) (d) Zirconium (Zr) (e) Aluminum (Al) Answer: (a) P: [Ne]3s^2 3p^3 (b) As: [Ar]4s^2 3d^10 4p^3 (c) Sn: [Kr]5s^2 4d^10 5p^2 (d) Zr: [Kr]5s^2 4d^2 (e) Al: [Ne]3s^2 3p^1

Step 1: Identify noble gases for each element

Firstly, locate each element in the periodic table and determine the noble gas that precedes each element. Here are the noble gases for each element: (a) P (phosphorus) -> Ne (neon) (b) As (arsenic) -> Ar (argon) (c) Sn (tin) -> Kr (krypton) (d) Zr (zirconium) -> Kr (krypton) (e) Al (aluminium) -> Ne (neon)

Step 2: Write electron configuration

Using the chosen noble gases, write the ground state electron configuration for each element in abbreviated form: (a) P -> [Ne]3s^2 3p^3 (b) As -> [Ar]4s^2 3d^10 4p^3 (c) Sn -> [Kr]5s^2 4d^10 5p^2 (d) Zr -> [Kr]5s^2 4d^2 (e) Al -> [Ne]3s^2 3p^1

Key Concepts

Periodic Table

The periodic table is an essential tool in chemistry that organizes elements based on their atomic number, electron configurations, and recurring chemical properties. It is structured into rows called periods and columns called groups.

• Periods: Horizontal rows where elements have the same number of atomic orbitals.
• Groups: Vertical columns where elements share similar chemical properties.

Elements are ordered by increasing atomic number, which is the number of protons in the nucleus. This layout allows us to predict the properties of elements and understand their electron configurations. For instance, elements in the same group often have similar valence electron configurations, affecting how they bond and interact. Finding the electron configuration of an element involves locating it on the periodic table and identifying its position relative to the noble gases. By using the periodic table as a guide, students can easily determine the electron arrangement and the abbreviated electron configuration of any element by starting with the noble gas of the preceding period.

Noble Gases

Noble gases are elements in Group 18 of the periodic table, characterized by their full valence shells, which make them very stable and unreactive.

• Common noble gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).
• They have complete outer electron shells, which inhibits them from forming bonds under normal conditions.

In terms of electron configuration, noble gases serve as reference points for shorthand notation. Instead of writing out all the electrons in an atom, chemists use the symbol of the closest preceding noble gas in brackets and then include the rest of the electron configuration. This shorthand is not only efficient but also highlights the valence electrons, which are the ones involved in bonding. For example, for phosphorus (P), the noble gas that precedes it is neon (Ne), so its abbreviated electron configuration starts with [Ne]. This exemplifies how understanding the position and properties of noble gases helps simplify electron configurations.

Ground State

The ground state of an atom is its lowest energy state, where all electrons are in the lowest energy levels possible. Electrons fill atomic orbitals in a specific order, starting with the lowest energy orbital available according to the Aufbau principle.

• The sequence is based on the increasing energies of the orbitals: 1s, 2s, 2p, 3s, 3p, etc.
• This order is influenced by the Pauli exclusion principle and Hund's rule, which dictate electron filling patterns.

In the ground state, electrons are configured in the least energy-demanding way, making the atom more stable. When writing the electron configuration for the ground state, it's important to remember that electrons fill the s orbital first, then move to p, d, and f orbitals as needed. Understanding this process helps predict the chemical behavior and bonding characteristics of an element. Identifying the ground state electron configuration also involves using the periodic table to recognize the electron distribution. This method ensures that electrons are not misplaced in higher energy levels unless absolutely necessary, reflecting the most stable, efficient arrangement of electrons.